So after tearing, hacking, slashing, stabbing, blasting, and shooting my way through Demon's Souls, I descend to the final dungeon, I'm without any Blue Phantoms at my side, I'm completely alone, I walk in and...

A bit of a both I think. Especially since most people would be expecting a boss battle that would rival the difficulty of going against 5 Maneaters and 7 Flamelurkers at once.

No, the last boss was probably cut, just like the world connected to the broken archstone in the Nexus.

So after tearing, hacking, slashing, stabbing, blasting, and shooting my way through Demon's Souls, I descend to the final dungeon, I'm without any Blue Phantoms at my side, I'm completely alone, I walk in and...

SPOILER WARNING: Click here to reveal hidden content.

it's a flopping, amorphous blob that couldn't mount a decent attack with nuclear detonation codes. Do you think this was done for dramatic effect, or do you think the devs are having a good laugh about making THIS the final boss in what has otherwise been a grueling game?

@Abyssfull: Oh that fucking Flame Lurker...I'd forgotten all about him (I've been playing this game off and on since it came out and I only just beat it).

I was extremely surprised as well I kind of laughed myself. I though he was just a taunt enemy and to then release a one hit kill but I guess he was just a dramatic joke.

Man need to check this sub forum more often.
 
Dramatic effect.  Like almost all of From Software's RPG's he was meant to represent a moral lesson/plot point in the story.  Look at Kings Field 4, Eternal Ring, both Shadow Towers, etc etc etc.  All RPG's by From, all had last bosses in this same vein.  You should consider False King to be the actual "last boss" in many ways he represents the power of that character anyway being his true demonic form and all.

King Allant was to me the final Boss. He's one of the hardest bosses I have ever seen in video games. And after reading what was above, I think it makes sense now that they made the final boss like it is. It does create a dramatic effect, just like when you confront Maiden Astraea and she kills herself after saying: "take your precious Demon soul". You kinda feel bad about her death and keep wondering what the hell you've been doing until now. It's genius