Alesha, Who Smiles at Death + Crystalline Crawler + Aggravated Assault + Arcbound Overseer + Bartolomé del Presidio

Alesha, Who Smiles at Death

Crystalline Crawler

Aggravated Assault

Arcbound Overseer

Bartolomé del Presidio

How it works

1. Activate Crystalline Crawler's second ability by tapping it, putting a +1/+1 counter on it.
2. Activate Bartolomé del Presidio by sacrificing Arcbound Overseer.
3. When Arcbound Overseer dies, it triggers, putting its +1/+1 counters on Crystalline Crawler.
4. Resolve the Bartolomé del Presidio ability.
5. Activate Crystalline Crawler's first ability five times by removing five +1/+1 counters from it, adding 3.
6. Activate Aggravated Assault by paying 3, causing you to untap all creatures you control and to get an additional combat and main phase after this one.
7. Declare Alesha as an attacker, triggering its ability, targeting Arcbound Overseer.
8. Activate Crystalline Crawler's first ability twice by removing two +1/+1 counters from it, adding W/BW/B.
9. Resolve the Alesha trigger, causing you to pay W/BW/B to return Arcbound Overseer from your graveyard to the battlefield tapped and attacking with six +1/+1 counters on it due to its modular ability.
10. Repeat.

This loop centers on Crystalline Crawler acting as a versatile mana engine, where its ability to produce any color of mana fuels Aggravated Assault to continually grant extra combat phases. To keep that mana flowing, Bartolomé del Presidio sacrifices Arcbound Overseer so its modular triggers can pile a mountain of +1/+1 counters right back onto Crystalline Crawler. Meanwhile, Alesha, Who Smiles at Death continuously snatches Arcbound Overseer right back out of the graveyard on every single combat, ensuring the artifact cycle never runs dry.