I have gone through the game thus far without a hitch. Sure when you get to Gran Pulse you need to think a little harder but the game is still forgiving. But here I am at the chapter 11 boss and he just keeps beating the shit out of me and raping my ass with a constant influx of status effects and lasers and buff-cancels and whatnot. What the hell?! Please give me some pointers.

Well by the boss I'm refering to the last boss of chapter 11. It's something you fought before. I'm trying to avoid spoilers.

First off, you'll want to make sure that your crystellium grid is nearly filled up for the main 3 jobs each character has at that point in the game. If it's not, go back and grind on some of the mobs around vanile/fangs home. The vampires are good to grind on in particular as they aren't too hard and give decent CP. For the boss himself, I used Lighting as party leader and brought along Vanile and Shaz. The best way to do damage for this boss, and pretty much most bosses in the game from that point is to start off with a Commando/Ravager/Ravager paradigm and do two rounds of attacks, then switch to a tri-ravager paradigm to quickly stagger the boss. You want to do two rounds of attacks before switching because of how the game mechanics work. Once you do two rounds of attacks and switch, your ATB gauge will be refilled complete and you'll be able to attack right away. It's a pretty nifty trick to exploit for some of the more challenging enemies. Also, I'm not sure if this is always true, but I found that the first time you switch paradigms in a battle, you have to watch each persons individual changing animation which is about a 5-6 second total without control/skill usage, while after that it happens instantly. Like I said, I don't know if this always hold true, but it's something to keep in mind when you need to switch for healing desperately and it's your first paradigm shift. Anyway, once you stagger the boss, get him to about a 400-500% rating (depending on how much time you have left for stagger), then switch to a di-commando/rav paradigm to dish out the real damage. Once the first stagger is over, I think he always does his buff wipe attack, so you probably don't want to do any buffing during the first stagger. Just repeat that general routine for dealing damage. For healing, I usually keep 3 different paradigms. I have a diversity (Com/rav/med) for light healing whilst still raising the combo meter, a com/syn/med paradigm so I can keep/start a combo meter while getting heals and buffs, and the "oh shit things are looking bad" med/med/syn to provide quick, emergency healing whilst getting buffed. For the oh shit paradigm, you'll be doing a bit of healing as well and I advise not using the auto-command function for it. Lighting seems to be slow at healing compared to the others, and by the time she turns around to heal someone, they will probably already be healing or someone else will need the healing more desperately. Also remember to ALWAYS heal yourself first if you hurt, as it's game over if you die. You'll probably want to use the oh shit paradigm when he does his chain gun-like face of doom attack. Also, Renew is a good option to use for healing if you have it and you are nearly dead. It'll pretty much top everyone off and has saved me a bunch of times.
 
I had a hard time with this asshole too, and I honestly didn't figure out how to take on bosses from pulse onward until about the end of chapter 12. What I do still probably isn't the best strategy as I'm not getting 5-stars on everything, but honestly killing the boss is all that matters to me at this point. The best thing to do really is at least master paradigm shifting at the right time in order to get a full atb bar when you switch. It might not seem like much time saved compared to just waiting for the atb to fill and switching whenever, but it really makes a difference.
 
Once you beat the boss, you unlock another level in the crystallium grid, so you should probably should go back and grind a bit in the gran pulse hub area as the bosses in the next area in the game are similar in a constant damage sense, but the constant damage is a lot more and comes even more frequently (because constant isn't enough for FF13 bosses, apparently).
 
I hope this helps you somehow and sorry if my explanation seems too long/convoluted/stupid/some kind of negative term. It's nearly 5 a.m as I type this and my out-of-wack sleeping patterns has been screwing with my brain.

My 2 cents...
Dazega..... Goddam Dazega........ I beat it with Snow as main maxed out in Sentinal, Vanielle as super hardcore Medic with powerful magic upgrades  (but with Snow it's not all that necessary) and most importantly ESUNA  and Lightning as Commando with maxed out weapon and strength upgrades.  Still took me about an hour.
 
Bottom line..... If you use Snow or Fang as your main character you will be able to relax a bit as there is little chance of instant death attacks or dropping below 1/4 HP if you level them up right.  Worst moment was spending 25 mins chipping away at this boss only to have instant death. Sure it will take a while but it's less of a whoop ass on your nerves.  And try to switch to a Ravager-Ravager-Ravager after some of the more weaker status attacks and build up the stagger chain as much as you can (2 or 3 attacks to be safe), remember to switch to a Medic user class just before he is un-staggered again.
I don't know if you noticed this or not i only realized last night.... summoning revives downed allies to full.... when the @#$% hits the fan, Summon for recovery rather than attacking.
 
Oh and if you can get Vanielle leveled as a Saboteur her attacks in that mode can really help speed up the rate he takes damage.

Big tip: Don't waste your TP on summons, use it on Dispelga. This goes for any boss that uses status effects.

Thanks people. I might go leveling up a little again.

I did it with Lightning, Snow and Hope. Snow was Sentinel most of the time, Hope was almost always on Medic, and Light was Commando. I used Diversity and set Snow to Ravager to get the chain up while Hope healed, and when things were looking grim it was either Combat Clinic or Solidarity. Preferably Solidarity because Light can keep that chain where it's at. When he's staggered, go Relentless Assault. 
 
And yeah, make sure you use Dispelga when you are hit with that massive status effect shot.

I just beat this the other day so while it is fresh lemme write down my thoughts for you if they help any (assuming you are still stuck here).
 
This fight is all about maximizing stagger time, he has a insanely low stagger number (200 or 250 I forget) and this is the first fight I found using a Sab absolutely mandatory. Essentially I started the fight with rav/rav/rav. I would quickly (about 2 sets of attacks) build up the stagger meter to almost full and then switch to Sab/Med/Sen. During this time I would absolutely make sure I got up de-protect up on him (AFTER he uses his skill to remove all debuff/buffs, since afterwards he won't use it again for another minute or so) and attempt to get imperil and de-shell on as well, if I couldn't though not a huge deal.  
 
At this point the Sab would get him to stagger where I would then switch to Com/rav/sen (I used Snow as my Sen, with accessories he has about 7500 hp so he can last a long time with just self healing) so I could focus on nothing but attacking. The rav was constantly building the stagger meter even during stagger and the majority of it with de-protect up my Com (lightning) was hitting for around 14,000 each attack and then scourging (even timed it so sometimes I could get 2 scourges before the stagger ran out) for 99,999 as long as de-protect was up, if it was not up the scourge would do about 35,000. 
 
Basically I just rinse and repeated that over and over until he died, I never dispelled status effects except for daze and used a summon once just for the free heal. This strategy also works especially well if you are underleveled, because lemme assure you I am 100% underleveled. I have done like 2 optional missions in pulse and that's it.

" First off, you'll want to make sure that your crystellium grid is nearly filled up for the main 3 jobs each character has at that point in the game. If it's not, go back and grind on some of the mobs around vanile/fangs home. The vampires are good to grind on in particular as they aren't too hard and give decent CP. For the boss himself, I used Lighting as party leader and brought along Vanile and Shaz. The best way to do damage for this boss, and pretty much most bosses in the game from that point is to start off with a Commando/Ravager/Ravager paradigm and do two rounds of attacks, then switch to a tri-ravager paradigm to quickly stagger the boss. You want to do two rounds of attacks before switching because of how the game mechanics work. Once you do two rounds of attacks and switch, your ATB gauge will be refilled complete and you'll be able to attack right away. It's a pretty nifty trick to exploit for some of the more challenging enemies. Also, I'm not sure if this is always true, but I found that the first time you switch paradigms in a battle, you have to watch each persons individual changing animation which is about a 5-6 second total without control/skill usage, while after that it happens instantly. Like I said, I don't know if this always hold true, but it's something to keep in mind when you need to switch for healing desperately and it's your first paradigm shift. Anyway, once you stagger the boss, get him to about a 400-500% rating (depending on how much time you have left for stagger), then switch to a di-commando/rav paradigm to dish out the real damage. Once the first stagger is over, I think he always does his buff wipe attack, so you probably don't want to do any buffing during the first stagger. Just repeat that general routine for dealing damage. For healing, I usually keep 3 different paradigms. I have a diversity (Com/rav/med) for light healing whilst still raising the combo meter, a com/syn/med paradigm so I can keep/start a combo meter while getting heals and buffs, and the "oh shit things are looking bad" med/med/syn to provide quick, emergency healing whilst getting buffed. For the oh shit paradigm, you'll be doing a bit of healing as well and I advise not using the auto-command function for it. Lighting seems to be slow at healing compared to the others, and by the time she turns around to heal someone, they will probably already be healing or someone else will need the healing more desperately. Also remember to ALWAYS heal yourself first if you hurt, as it's game over if you die. You'll probably want to use the oh shit paradigm when he does his chain gun-like face of doom attack. Also, Renew is a good option to use for healing if you have it and you are nearly dead. It'll pretty much top everyone off and has saved me a bunch of times.  I had a hard time with this asshole too, and I honestly didn't figure out how to take on bosses from pulse onward until about the end of chapter 12. What I do still probably isn't the best strategy as I'm not getting 5-stars on everything, but honestly killing the boss is all that matters to me at this point. The best thing to do really is at least master paradigm shifting at the right time in order to get a full atb bar when you switch. It might not seem like much time saved compared to just waiting for the atb to fill and switching whenever, but it really makes a difference. Once you beat the boss, you unlock another level in the crystallium grid, so you should probably should go back and grind a bit in the gran pulse hub area as the bosses in the next area in the game are similar in a constant damage sense, but the constant damage is a lot more and comes even more frequently (because constant isn't enough for FF13 bosses, apparently).  I hope this helps you somehow and sorry if my explanation seems too long/convoluted/stupid/some kind of negative term. It's nearly 5 a.m as I type this and my out-of-wack sleeping patterns has been screwing with my brain. "

I'm already struggling on chapter 9 and 10 boss, if chapter 11 boss is that difficult, i'm also going to snap my disc in half. Of course I can't afford to, however the bosses in this game are very difficult and unfair.

I don't really like the bosses in this game. I prefered the bosses in previous Final Fantasy's because they could be beaten with brute force, now you have to do 10 battles of trial and error to figure out how to beat something.

"

I'm already struggling on chapter 9 and 10 boss, if chapter 11 boss is that difficult, i'm also going to snap my disc in half. Of course I can't afford to, however the bosses in this game are very difficult and unfair.

"

Just realized this wasn't the strat I ended up using for the fight, it was one I had planned to try late last night.  Removing it now so I don't mislead anyone else.

Are you all talking about the fight at the top of the tower, or am I confused? 
 
Because that boss was a complete and utter pushover, and took me one try. Yeah, 2.3 million is a lot of health, but if you just... you know, think while playing the game it's not that hard.

Exactly.

" @HitmanAgent47 said:

"

I'm already struggling on chapter 9 and 10 boss, if chapter 11 boss is that difficult, i'm also going to snap my disc in half. Of course I can't afford to, however the bosses in this game are very difficult and unfair.

"

The entire game is a grind fest.  If you don't grind, you lose. "

You see I used Lightnig, Hope, and Fang. You know why? Hope has massive magic as he goes along in the Paradigm grid. Same with Fang's strength. Buy 3 Warriors Wristband and 3 Sorcerer's Mark before you go into battle. If you have the Entite ring then sell that bitch. It will grab you 60,000 Gil (don't worry, you can either buy it back later on for 120,000 gil or upgrade from a Growth Egg, but I suggest you don't do that because that Growth Egg offers the "CP X2" ability). If you have all 3 accessory slots unlocked for all characters then put the 3 Warrior Wristbands on Fang and the 3 Sorcerer's Mark on Hope. That should put the Strength and Magic above 1000. Give Lightning whatever you deem necessary.  Make sure you have these Paradigms - Relentless Assault, Combat Clinic, Evened Odds, Mystic Tower, Protector, Delta Assault. 
 
When you get into battle switch to Evened Odds. As soon as Hope puts on all the buffs then switch to Delta Assault for a couple of rounds then switch to Mystic Tower. Basically you want Fang to take the brute of the damage. She's considered your meat shield. You basically have to keep knocking this guy into a stagger. Anytime you need healing just switch to Combat Clinic so Lightning and Hope can do all the healing. When your done continue the process. When he puts the Doom counter on Lightning switch to Relentless Assault and go all out. You may need to switch to Combat Clinic to heal once or twice. 
 
The reason why I say Relentless Assault is because you need one Commando in the party to slow down the Stagger meter and 2 Ravager's to build it up quick. If you have 3 Ravagers then by the time their ATB gauge fills up, his stagger meter will have already drained. If you still happen to fall in battle then most likely you need to work on your Crystarium. If you already farmed all the CP you can then try the Protector paradigm. Basically have Fang deal s slew of status effects on the boss (I don't know if the status effects works, it's just something to try).

I had a feeling the Chapter 11 boss would be a pain. As soon as I saw how open the game got at this point and the introduction of missions I immediately walked the opposite direction from the mission marker and started to take up quests instead. Of course, the introduction of grinding started my natural reaction to the activity: I started to play the game way less often. Hopefully Ill have my team up to snuff before any sort of boredom sets in.

" Are you all talking about the fight at the top of the tower, or am I confused? 
 
Because that boss was a complete and utter pushover, and took me one try. Yeah, 2.3 million is a lot of health, but if you just... you know, think while playing the game it's not that hard. "

" @HitmanAgent47 said:

"

I'm already struggling on chapter 9 and 10 boss, if chapter 11 boss is that difficult, i'm also going to snap my disc in half. Of course I can't afford to, however the bosses in this game are very difficult and unfair.

"

The entire game is a grind fest.  If you don't grind, you lose. "

I beat this guy the first time with Lighting, Snow, and Vanille. I also didn't max out my crystarium.

"

I'm already struggling on chapter 9 and 10 boss, if chapter 11 boss is that difficult, i'm also going to snap my disc in half. Of course I can't afford to, however the bosses in this game are very difficult and unfair.

"

I think i'm at the chapter 11 boss, I almost won the fight, with only one cm of power or less, then he cast doom. I hate all the bosses from this game, what are they trying to do? Fustrate you? That was totally retarded and a waste of my time.

Yea, it there's anything satisfying about this game its the bosses.  Their pretty hard, but it truly brings out how great the battle system is.  That said, I also cannot beat this boss haha.  I know exactly what to do, and I will be winning, but then he casts doom because I'm taking too long.  I have no idea why they decided to do that.  If my characters aren't DEAD, and the boss is dying I'm obviously DOING IT RIGHT!

"  I have no idea why they decided to do that."