Everyone except Steiner who goes into trance receives a 50% bonus to their attack strength. Steiner receives a 300% bonus (except while using the Blood Sword, which has a different damage calculation).

Quina's Eat turns into Cook. Eat allows Quina to eat a monster who's at 1/4 of its HP. Cook allows Quina to eat a monster who's at 1/2 of its HP.

As said before, when Garnet summons an eidolon under trance it will be summoned with a slightly different animation, with slightly altered attack power. And then after that, as long as Garnet doesn't summon a new one, that eidolon will randomly summon itself again. The only good thing about the random summon is that it doesn't use any more of the trance gauge, so if Garnet doesn't do anything else that Eidolon can summon itself for the remainder of the battle.