Exhaust abilities can be activated any time you could normally activate an ability.
2025-02-07
If an exhaust ability of a permanent is activated, and then that permanent leaves the battlefield and returns to the battlefield, it becomes a new object so its exhaust ability can be activated again.
2025-02-07
If an ability triggers whenever you activate an exhaust ability, that ability resolves before the exhaust ability resolves.
During your turn, as long as you haven't activated an exhaust ability this turn, you may activate exhaust abilities as though they haven't been activated.
Exhaust — : Put a +1/+1 counter on this creature. (Activate each exhaust ability only once.)
: Put a +1/+1 counter on this creature. (Activate each exhaust ability only once.)