So about Odin's attacks..

[Cherie]

Odin does attacks? All I see are flashing lights, which I assume cause people to have seizures randomly and pass out.

lol, um seriously though... I forget the names, but Odin has a few basic moves:

1) AoE immobilize that can also petrify?
2) Circular "cage" that you have to break the tether to get out?
3) Melee attack that is instant death to most non tanks.
4) Odin's "Limit Break" when he is low health that kills everyone in range (You should be able to run away from it if it looks hopeless. Think of the movie predator and his last move! lol).
5) There are also some random debuffs that increase your damage taken for a while.

Beyond those, I think there are little AoE circles that he throws around also that have a fair chance of killing you too, but often you can limp away.

Sorry I don't know all the moves by name.

Something also to consider is how you mentioned how some attacks seem to do nothing. I believe you are right, but this is because there are too many people around and it can only effect so many people at once that get hit by it. It should cap out, much like Odin can only take so many dps dots at once.