Dawnsire, Sunstar Dreadnought + Vigor + Crystalline Crawler + Aggravated Assault

Dawnsire, Sunstar Dreadnought

Vigor

Crystalline Crawler

Aggravated Assault

How it works

1. Declare any creature as an attacker. Dawnsire triggers, attempting to deal 100 damage to Crystalline Crawler, which will result in 100 +1/+1 counters being placed on it instead due to Vigor.
2. Move to your postcombat main phase.
3. Activate Crystalline Crawler's first ability five times by removing five +1/+1 counters from it, adding 3.
4. 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.
5. Repeat.

This explosive loop relies on Dawnsire, Sunstar Dreadnought's attack trigger to target Crystalline Crawler, dealing a massive 100 damage that Vigor cleverly intercepts and converts into an overwhelming pile of 100 +1/+1 counters instead of destroying it. Crystalline Crawler then cashes in just a fraction of those newly minted counters for mana, effortlessly funding Aggravated Assault to untap your board and grant you an endless sequence of additional combat phases. Because Dawnsire, Sunstar Dreadnought triggers anew each time you declare attackers in these extra combats, you can repeat the process indefinitely to generate infinite mana, infinite combat steps, and infinitely large creatures.