Round 3 encounter is Siren. Siren can inflict poison.
Burst Frog & Water God can be encountered instead of Siren, with a chance of capturing one of them.
Eliza can attack up to 4 times per turn.
Eliza will occasionally use her AOE BB Freezing Point in tandem with her normal attack. Both have chance to inflict poison. She may also use a stronger version called Permafrost every fourth turn. Note that the turn that she uses Abyss Edge doesn't count toward the interval.