Alesha triggers, causing you to pay ({WB} magic symbol) ({WB} magic symbol) to return Dockside Extortionist from your graveyard to the battlefield tapped and attacking.
When Dockside Extortionist enters the battlefield, it triggers, creating at least seven Treasure tokens.
Move to your postcombat main phase.
Activate Bartolomé del Presidio by sacrificing Dockside Extortionist, putting a +1/+1 counter on it.
Activate five Treasures by tapping and sacrificing them, adding ({3} magic symbol) ({R} magic symbol) ({R} magic symbol) .
Activate Aggravated Assault by paying ({3} magic symbol) ({R} magic symbol) ({R} magic symbol) , causing you to untap all creatures you control and to get an additional combat and main phase after this one.
Move to your next combat phase.
Declare Alesha as an attacker.
Alesha triggers, holding priority, activate two Treasures by tapping and sacrificing them, adding ({WB} magic symbol) ({WB} magic symbol) .
Resolve the Alesha trigger, causing you to pay ({WB} magic symbol) ({WB} magic symbol) to return Dockside Extortionist from your graveyard to the battlefield tapped and attacking.
Repeat from step 3.
Results
Infinite LTB.
Infinite ETB.
Infinite colored mana.
Infinite sacrifice triggers.
Infinite death triggers.
Infinite combat phases.
Infinite Treasure tokens.
Infinite +1/+1 counters on Bartolomé del Presidio.