Cauldron of Souls

If a nontoken creature that gains persist this way is put into a graveyard, that card will be returned to the battlefield with a -1/-1 counter on it. However, because it’s a new object with no relation to its previous existence, the returned creature will not have persist.

If a token with no -1/-1 counters on it has persist, the ability will trigger when the token is put into the graveyard. However, the token will cease to exist and can’t return to the battlefield.

If a permanent has multiple instances of persist, they’ll each trigger separately, but the redundant instances will have no effect. If one instance returns the card to the battlefield, the next to resolve will do nothing.