So i noticed that you can summon red phantoms. Are they enemies or just like white or yellow phantoms?

enemies

They are dark spirits. I'm guessing they are in a Dark covenant thing. Once I beat the game I saw the red signs and the dragon eye signs all over the place for some PvP.

From my experience, which is probably completely arbitrary, the red sign guys always seemed harder than the dragon covenant guys. Plus, when you summon a red sign they spawn elsewhere in the level. The dragon signs always spawned where the sign is made. Not sure why as I have not been in either covenant.

It's really a bad deal summoning those guys in. You drop your humanity if you lose and almost every one I've seen has been an aggressively min-maxed PVP build. One of them even 3 shotted my dragon ring with mele somehow. Not fun

Yeah, they're dark spirits. It's no different than if you were invaded by one, only you of course have a little more control over the fight since you're the one willingly inviting them into your world. Though again, they're the same as if you were invaded, so they can't use estus flasks (but can still use healing miracles) however enemy NPCs will not react to them, so they may also sometimes escape to bunker next to an enemy NPC mob.

They're placed down because unlike in prior Souls games, the items used to invade others are finite, and while in NG+ you can buy more for 10K souls each, you can alternatively place down a red summon sign instead as many as times you want. Plus, some people just really enjoy the PVP and would like to fight a little more 'honourably' as opposed to invading some guy in the middle of their playthrough.

Winning the bout will still reward them tokens of spite anywhoo, so it's there as an alternative for trying to level up the Brotherhood of Blood covenant. What's funny is you could also potentially summon in some friendly white/yellow phantoms as well, even before you've summoned the dark spirit player, if you're in an especially cruel mood ;P

?

There is no humanity item in Dark Souls II. You lose part of your overall humanity whenever you die. This also includes dark spirits, but it also happens when you play offline and die.

Also, the myth that you need a specific build for PvP is just that. A myth. I've never created a character for PvP. Always just what I like to use. If I can do more DPS with a certain weapon, but like the look and feel of another weapon better, I'll still use the latter. I've never used armor that has high stats. Always pick the one I like the look of.

In the end, I still win the majority of times I'm invaded.

I think he meant that you can lose your "human" status, and possible souls. It's weird how they have little risk associated with them.