You control at least one creature token with base power 3 or less.
Xavier Sal does not have summoning sickness.
There is a removable counter on a permanent you control.
Steps
Activate
Xavier Sal by tapping it and removing a counter from a permanent you control, creating a copy of a creature token you control with base power 3 or less.
When the creature token enters the battlefield,
Intruder Alarm and
Overseer of Vault 76 trigger.
Resolve the
Intruder Alarm trigger, untapping all creatures.
Resolve the
Overseer of Vault 76 trigger, putting a counter on it.
Repeat.
Results
Infinite ETB.
Infinite creature tokens.
Infinite untap of creatures.
Infinite mana creatures you control can produce.
Infinite copies of creature tokens you control.
Infinite untap of creatures you control.
Metadata
In 0 decks according to EDHREC.
Bracket Tag
This combo has been estimated to be Exhibition (Bracket 1+).