Deathreap Ritual — ruling 1

If a creature didn't die before a turn's end step begins, Deathreap Ritual's ability doesn't trigger at all. The creature may have died before Deathreap Ritual entered the battlefield, however.

Deathreap Ritual — ruling 2

You draw one card when the ability resolves, not one card per creature that died during the turn.

Deathreap Ritual : règles, fonctionnement et interactions (MTG)

Deathreap Ritual 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

Morbid — At the beginning of each end step, if a creature died this turn, you may draw a card.

How it works : Deathreap Ritual

Original English text — Wizards of the Coast / Scryfall

#1August 7, 2020· Wizards of the Coast
If a creature didn't die before a turn's end step begins, Deathreap Ritual's ability doesn't trigger at all. The creature may have died before Deathreap Ritual entered the battlefield, however.
No other card is named in this ruling.
#2August 7, 2020· Wizards of the Coast
You draw one card when the ability resolves, not one card per creature that died during the turn.
No other card is named in this ruling.