Pretty strange, look into it.
Played sotf, and the holy type auto poisoner entered the field, while he got poisoned.
My line: stormloch, shiva, mossgiliath, and solariel. I didnt have AP at my team.
His line: icefang, raizen, the AP who entered, and i think GF… not sure… was end game.
Dont know if you reading this hit it happened now too, this time wothout AP.
Utopion entered the field and got poisoned. I didnt had any AP at the battle (shiva, chronozeraus, mecha and The electric se protector).
Enemy had bane (already on field), and dont remember what else.
It was an uptopion i knockbacked at the start of the battle if it helps, he had half hp and after i knocked him back - bane entered. (Double knockback).