Dusk Legion Sergeant — ruling 1

If a card with persist is removed from the graveyard after it dies but before the ability trigger resolves, it won't be returned to the battlefield.

Dusk Legion Sergeant — ruling 2

Once persist returns the creature, it's considered a new object with no relation to the object that it was. Auras that were attached to it won't return to the battlefield. Equipment that was attached to it will remain unattached. Any counters that were on it won't be put on the new creature.

Dusk Legion Sergeant — ruling 3

If a creature has +1/+1 counters and -1/-1 counters on it, state-based actions remove the same number of each so that it has only one kind of those counters on it. A creature's persist ability can bring it back again if its -1/-1 counters are removed this way.

Dusk Legion Sergeant — ruling 4

If a creature with persist that has +1/+1 counters on it receives enough -1/-1 counters to cause it to be destroyed by lethal damage or put into its owner's graveyard for having 0 or less toughness, persist won't trigger and the card won't return to the battlefield. That's because persist checks the creature as it last existed on the battlefield, and it still had -1/-1 counters on it at that point.

Dusk Legion Sergeant : règles, fonctionnement et interactions (MTG)

Dusk Legion Sergeant is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Menace , Sacrifice this creature: Each nontoken Vampire creature you control gains persist until end of turn. (When it dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

How it works : Dusk Legion Sergeant

Original English text — Wizards of the Coast / Scryfall

#1November 10, 2023· Wizards of the Coast
If a card with persist is removed from the graveyard after it dies but before the ability trigger resolves, it won't be returned to the battlefield.
No other card is named in this ruling.
#2November 10, 2023· Wizards of the Coast
Once persist returns the creature, it's considered a new object with no relation to the object that it was. Auras that were attached to it won't return to the battlefield. Equipment that was attached to it will remain unattached. Any counters that were on it won't be put on the new creature.
No other card is named in this ruling.
#3November 10, 2023· Wizards of the Coast
If a creature has +1/+1 counters and -1/-1 counters on it, state-based actions remove the same number of each so that it has only one kind of those counters on it. A creature's persist ability can bring it back again if its -1/-1 counters are removed this way.
No other card is named in this ruling.
#4November 10, 2023· Wizards of the Coast
If a creature with persist that has +1/+1 counters on it receives enough -1/-1 counters to cause it to be destroyed by lethal damage or put into its owner's graveyard for having 0 or less toughness, persist won't trigger and the card won't return to the battlefield. That's because persist checks the creature as it last existed on the battlefield, and it still had -1/-1 counters on it at that point.
No other card is named in this ruling.