Pestilent Cauldron // Restorative Burst — ruling 1

Pestilent Cauldron’s second ability counts the total amount of life gained without considering any life you lost during that turn. For example, if you lost 2 life and gained 2 life earlier in the turn, your opponents will mill two cards.

Pestilent Cauldron // Restorative Burst — ruling 2

You must be able to target four cards in a single graveyard in order to activate Pestilent Cauldron’s last ability.

Pestilent Cauldron // Restorative Burst — ruling 3

You may cast Restorative Burst with no targets. If you do, each player will gain 4 life and you’ll exile Restorative Burst. However, if you choose one or two target cards, and each of those cards is an illegal target as Restorative Burst tries to resolve (usually because something else moved them in response), Restorative Burst won’t resolve and none of its effects will happen. No one will gain life, and Restorative Burst won’t be exiled.

Pestilent Cauldron // Restorative Burst : règles, fonctionnement et interactions (MTG)

Pestilent Cauldron // Restorative Burst 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

, Discard a card: Create a 1/1 black and green Pest creature token with "When this token dies, you gain 1 life." , : Each opponent mills cards equal to the amount of life you gained this turn. , : Exile four target cards from a single graveyard. Draw a card. Return up to two target creature, land, and/or planeswalker cards from your graveyard to your hand. Each player gains 4 life. Exile Restorative Burst.

How it works : Pestilent Cauldron // Restorative Burst

Original English text — Wizards of the Coast / Scryfall

#1April 16, 2021· Wizards of the Coast
Pestilent Cauldron’s second ability counts the total amount of life gained without considering any life you lost during that turn. For example, if you lost 2 life and gained 2 life earlier in the turn, your opponents will mill two cards.
Card named in this ruling
Pest
#2April 16, 2021· Wizards of the Coast
You must be able to target four cards in a single graveyard in order to activate Pestilent Cauldron’s last ability.
Card named in this ruling
Pest
#3April 16, 2021· Wizards of the Coast
You may cast Restorative Burst with no targets. If you do, each player will gain 4 life and you’ll exile Restorative Burst. However, if you choose one or two target cards, and each of those cards is an illegal target as Restorative Burst tries to resolve (usually because something else moved them in response), Restorative Burst won’t resolve and none of its effects will happen. No one will gain life, and Restorative Burst won’t be exiled.
No other card is named in this ruling.