Kami of Celebration
Creature — Spirit
Whenever a modified creature you control attacks, exile the top card of your library. You may play that card this turn. (Equipment, Auras you control, and counters are modifications.)
Whenever you cast a spell from exile, put a +1/+1 counter on target creature you control.
Milivoj Ćeran
Rulings
An Aura controlled by an opponent does not cause a creature you control to be modified.
(wotc • 2022-02-18)
You must still pay all costs and follow all normal timing rules to play a card this way. For example, you may play a land this way only during your own main phase while the stack is empty, and only if you have not yet played a land this turn.
(wotc • 2022-02-18)
A creature with a counter on it is considered modified no matter what kind of counter it is or which player put it on that creature.
(wotc • 2022-02-18)
A creature that is equipped is considered modified no matter who controls the Equipment that's attached to it.
(wotc • 2022-02-18)
Rulings
An Aura controlled by an opponent does not cause a creature you control to be modified.
(wotc • 2022-02-18)
You must still pay all costs and follow all normal timing rules to play a card this way. For example, you may play a land this way only during your own main phase while the stack is empty, and only if you have not yet played a land this turn.
(wotc • 2022-02-18)
A creature with a counter on it is considered modified no matter what kind of counter it is or which player put it on that creature.
(wotc • 2022-02-18)
A creature that is equipped is considered modified no matter who controls the Equipment that's attached to it.
(wotc • 2022-02-18)