Poison

Poison is a skill where a character can poison one, or more, characters on the opposing team.

When the enemy has Resiliance buff (the +1 can't be killed), the Poison attack will kill them before their attack if their health is below the amount of damage dealt by poison and the Resiliance buff is bypassed.

Poison deals 0.5x characters ATK in fixed damage to the poisoned targets each turn.

Venom or strong poison, and deals 5x characters ATK to the poisoned targets each turn. Venom and poison cannot be used at the same time (as the debuffs icons are same).

Toxic or progressive posion deals incrementally higher amounts of damage to its targets, starting at 0.5x, improving by 3x and for most strong characters (with ATK 1000+) reaching max of 1.5m after 8 or so turns. It can be used on targets that have been poisoned already (as the debuff icons are different).

Some characters increase damage to targets affected by a specific type of poison (one of said three).

Some enemies can cast poison on you, usually it deals from few hundred to few k damage each turn. This is rare, can be removed by several specials, and is generally not seen as a serious problem making anti-poison sockets weak.