Maester Seymour + Crystalline Crawler + Hellkite Charger Combo

All permanents on the battlefield (Maester Seymour with power 5 or greater on the battlefield).

At the beginning of your combat phase, Maester Seymour triggers, putting at least seven +1/+1 counters on Crystalline Crawler.

Declare Hellkite Charger as an attacker, triggering its ability.

Holding priority, activate Crystalline Crawler's first ability seven times by removing seven +1/+1 counters from it, adding .

Resolve the Hellkite Charger trigger, causing you to pay to untap all attacking creatures you control and to get an additional combat phase after this one.

Repeat.

Infinite colored mana

Infinite combat phases

Infinite +1/+1 counters on creatures you control