Rite of the Moth
Sorcery
Return target creature card from your graveyard to the battlefield with a finality counter on it. (If a creature with a finality counter on it would die, exile it instead.)
Flashback 
(You may cast this card from your graveyard for its flashback cost. Then exile it.)
A. M. Sartor
Rulings
Multiple finality counters on a single permanent are redundant.
(wotc • 2024-09-20)
Finality counters aren't keyword counters, and a finality counter doesn't give any abilities to the permanent it's on. If that permanent loses its abilities and then would go to a graveyard, it will still be exiled instead.
(wotc • 2024-09-20)
Finality counters work on any permanent, not only creatures. If a permanent with a finality counter on it would be put into a graveyard from the battlefield, exile it instead.
(wotc • 2024-09-20)
Finality counters don't stop permanents from going to zones other than the graveyard from the battlefield. For example, if a permanent with a finality counter on it would be put into its owner's hand from the battlefield, it does so normally.
(wotc • 2024-09-20)
Rulings
Multiple finality counters on a single permanent are redundant.
(wotc • 2024-09-20)
Finality counters aren't keyword counters, and a finality counter doesn't give any abilities to the permanent it's on. If that permanent loses its abilities and then would go to a graveyard, it will still be exiled instead.
(wotc • 2024-09-20)
Finality counters work on any permanent, not only creatures. If a permanent with a finality counter on it would be put into a graveyard from the battlefield, exile it instead.
(wotc • 2024-09-20)
Finality counters don't stop permanents from going to zones other than the graveyard from the battlefield. For example, if a permanent with a finality counter on it would be put into its owner's hand from the battlefield, it does so normally.
(wotc • 2024-09-20)