Redshift, Rocketeer Chief
Legendary Creature — Goblin Pilot
Vigilance
: Add X mana of any one color, where X is Redshift's power. Spend this mana only to activate abilities.
Exhaust — — 
: Put any number of permanent cards from your hand onto the battlefield.
Wayne Reynolds
Aetherdrift Promos (PDFT)
• #218pRulings
If an ability triggers whenever you activate an exhaust ability, that ability resolves before the exhaust ability resolves.
(wotc • 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.
(wotc • 2025-02-07)
Exhaust abilities can be activated any time you could normally activate an ability.
(wotc • 2025-02-07)
Rulings
If an ability triggers whenever you activate an exhaust ability, that ability resolves before the exhaust ability resolves.
(wotc • 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.
(wotc • 2025-02-07)
Exhaust abilities can be activated any time you could normally activate an ability.
(wotc • 2025-02-07)