Orthion, Hero of Lavabrink | Priest of Urabrask | Thornbite Staff

(and one other card)

Activate
Orthion's first ability by paying ({1} magic symbol) ({R} magic symbol) and tapping it, creating a token copy of
Priest of Urabrask with haste.
When the token
Priest of Urabrask enters the battlefield, it triggers, adding ({R} magic symbol) ({R} magic symbol) ({R} magic symbol) .
Activate
Altar of Dementia by sacrificing the
Priest of Urabrask token.
When the
Priest of Urabrask token dies,
Orthion triggers, untapping itself.
Resolve the
Altar of Dementia ability, causing target player to mill cards equal to the
Priest of Urabrask token's power.
Repeat.
Once you have infinite colored mana, you may instead use
Orthion's second ability to make copies of any creature(s) you control.