Tanks

[Kanly]

Right now I am running a NMI group through e2. I've never played through this part of the game before and I'm finally getting to fights that I am struggling to get through with just one tank.

In your opinion are two tanks mandatory? Are there specific fights that require multiple tanks?

[vintoks]

You can do it with one tank, but it is a good idea to groom an "off-tank" at least. Someone who can take a round or two of beating unaided, priest or rogue. There will be scripted fights where you can get surrounded in episode 2.

[En1gma]

Personally I strive for balance. I prefer using two tanks, or at least a study off-tank who can take some hits, allowing me to develop ranged or support characters to assist them.

I have been able to make a single tank work, but it is a chore and a half, because everyone else must focus on debuffs and major damage output- enough to make up for not having a second character to hold a flank.

Viability drops quickly once you get into E2, as more often than not you will be forced to hold multiple flanks against enemies who refuse to stand in one place and attack the closest character to them.

[Cory Trese]

Single tank in E2 and E3 is very difficult to manage, I think you'll die a lot.

You need someone else who can at least soak up hits, even if they don't deal damage.

[fallen]

I answered "you can do it with 1" because you can, but I might be confused on the strict definition of tank.

[anrdaemon]

The question is ambiguous at least.
What YOU define as tank? A character that can take the front line? Who can sit there, do nothing but laugh at the enemies? Aside from being very stupid idea it doesn't even begin to grow given current set of heroes. Vraes is the closest you can get to such a definition of a tank. But you can't sit there and soak up any damage coming in - if you are not killing mobs, you will just die.
Now, if we get this a little more straightforward… a character you can strategically place to split incoming damage is a much more viable tactic. But that is not necessarily a "tank" character. I would not dare to leave Tamilin on the frontline, but I'm not afraid of a mob going loose and running up on her. I could even move her up to an archer that would otherwise likely to target KJ or Kyera. Not that they can't take a little beating, but only a little. Two shots may be too much for KJ, and Kyera is unlikely to be happy either.
In short, yes, you can run with only one "true" tank, but it takes a little more consideration and thinking on your toes.

[Blitz]

I'm running with Selen as my main tank. Pumped up quicksilver defense and Warden's Shield and now she barely ever gets hit. Then TK Kincaid can occasionally be my off tank as he has pretty high dodge stats with Cunning Footwork and I pumped Constitution on Kyera with the heaviest armor and she can take a couple of hits too. Basically, Kjartan should never get hit except those pesky off targeting enemies for which I have high level pure flame shield and decent HP/armor gear on him. Basically, I have one main tank and two relief tanks I need to position the relief tanks carefully but that's okay as I've got two.