All permanents on the battlefield (Auton Soldier as a copy of Mondrak).
You have at least two opponents.
Auton Soldier does not have summoning sickness.
Steps
Declare Auton Soldier as an attacker.
Auton Soldier's myriad ability triggers, creating four token copies of itself as a nonlegendary copy of Mondrak attacking each other opponent.
When the Auton Soldier tokens enter the battlefield, Rose Room Treasurer triggers that many times.
Resolve the first two triggers, creating 2^(the number of Mondraks you control plus one) Treasure tokens.
Holding priority, activate any number of Treasure tokens by tapping and sacrificing them, adding ({1} magic symbol) for each Treasure sacrificed this way.
Resolve the next Rose Room Treasurer trigger, choosing to pay ({X} magic symbol) to deal X damage to any target.
Repeat steps 5 and 6 as desired for each remaining trigger.