Stensia

Whenever a creature deals damage to one or more players for the first time each turn, put a +1/+1 counter on it.
Whenever chaos ensues, each creature you control gains "{T}: This creature deals 1 damage to target player or planeswalker" until end of turn.

Whenever a creature deals damage to one or more players for the first time in a turn, put a +1/+1 counter on it.
Whenever you roll chaos, each creature you control gains "{T}: This creature deals 1 damage to target player" until end of turn.

March of the Machine Commander

Planechase Anthology Planes

Whenever a creature deals damage to one or more players for the first time in a turn, put a +1/+1 counter on it.
Whenever you roll CHAOS, each creature you control gains "{T}: This creature deals 1 damage to target player" until end of turn.