March: Frida, blue Panther (actually, rat), average mana. Her class is paladin. She does damage to 3 targets (higher than Panther, since she is average), blue elemental debuf, dispels and has intrinsic resistance to attack ailments. Elemental link gives resistance against nature. Better alternative to Arthur for raiding (I would still prefer Arthur for titans).
April: Anzogh, red wizard, slow mana. He does AoE attack, heals each ally with 20% of total damage done, reduces enemy critical chance and has intrinsic resistance to mana effects. Aditionally, elemental link gives defence against Ice.