Tawnos, Solemn Survivor | Intruder Alarm | Priest of Urabrask

Cards

Priest of Urabrask in your graveyard.
Tawnos and
Intruder Alarm on the battlefield.
Tawnos does not have summoning sickness.
You control at least two artifact tokens.
({1} magic symbol) ({W} magic symbol) ({U} magic symbol) ({B} magic symbol) available.

Activate
Tawnos' second ability by paying ({1} magic symbol) ({W} magic symbol) ({U} magic symbol) ({B} magic symbol) , sacrificing two artifact tokens, and exiling
Priest of Urabrask from your graveyard, creating a token copy of
Priest of Urabrask that is an artifact in addition to its other types.
The
Priest of Urabrask token enters the battlefield, triggering itself and
Intruder Alarm.
Resolve the
Priest of Urabrask trigger, adding ({R} magic symbol) ({R} magic symbol) ({R} magic symbol) .
Resolve the
Intruder Alarm trigger, untapping all creatures.
Activate
Tawnos' first ability by paying ({2} magic symbol) and tapping it, creating a token copy of the
Priest of Urabrask token, and causing you to mill two cards.
Repeat from step 2.
Once you have infinite red mana, you may instead choose any other artifact token(s) to make infinite copies of them.