Declare Mardu Siegebreaker as an attacker, triggering its second ability, creating a token copy of Rose Room Treasurer tapped and attacking each opponent.
When the Rose Room Treasurer tokens enter the battlefield, they each trigger for each other token that entered the battlefield, and any other Rose Room Treasurer(s) you control trigger for each token that entered the battlefield.
Resolve a Rose Room Treasurer trigger, creating a Treasure token if its the first or second time that ability has resolved this turn, or choosing not to pay otherwise.
Repeat step 3 for each remaining trigger.
Move to your postcombat main phase.
Activate five Treasures by tapping and sacrificing them, adding {3}{R}{R}.
Activate Aggravated Assault by paying {3}{R}{R}, causing you to untap all creatures you control and to get an additional combat and main phase after this one.
Repeat.

Near-infinite ETB

Near-infinite LTB

Near-infinite death triggers

Near-infinite sacrifice triggers

Near-infinite colored mana

Near-infinite Treasure tokens

Near-infinite combat phases

Near-infinite untap of creatures you control

Near-infinite mana creatures you control can produce

Mardu Siegebreaker

Aggravated Assault

Rose Room Treasurer

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} for each Treasure sacrificed this way.
Resolve the next Rose Room Treasurer trigger, choosing to pay {X} to deal X damage to any target.
Repeat steps 5 and 6 as desired for each remaining trigger.

Near-infinite damage

Mondrak, Glory Dominus

Auton Soldier

Declare Auton Soldier as an attacker.
Auton Soldier's myriad ability triggers, creating four token copies of itself as a nonlegendary copy of Adrix and Nev 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 Adrix and Nevs you control plus one) Treasure tokens.
Holding priority, activate any number of Treasure tokens by tapping and sacrificing them, adding {1} for each Treasure sacrificed this way.
Resolve the next Rose Room Treasurer trigger, choosing to pay {X} to deal X damage to any target.
Repeat steps 5 and 6 as desired for each remaining trigger.

Adrix and Nev, Twincasters

Combos with "Rose Room Treasurer"