Poison
Bang's Poison Nail slowly drains the opponent's life until either the maximum amount of life has been dealt (800 damage) or the opponent hits Bang. Poison can also never kill the opponent. Bang's Poison Nail is currently the only attack that deals poison status in the entire game.
Hitting Two Opponents With the Same Attack
Attacks can hit multiple targets assuming they are within range. For example an attack can hit BOTH Carl and Nirvana.
Normally, when an attack touches the opponent, the remaining active frames are converted into recovery frames. However, if there is a second hittable character, then the remaining active frames can still hit him!
This leads to visually strange situations like Jin's 5C hitting Nirvana, then a moment later, Carl jumps into the active frames and gets hit. This is further compounded by the fact that hitstop only applies to the attacker and the target, thus allowing the attack to hit the unaffected character with the active frames plus the hitstop frames!
This even applies to projectiles like Jin's Hishouken, but since the projectile will shatter the instant it touches Nirvana or Carl, this effect is much harder to take advantage of.