Crystalline Crawler has at least five +1/+1 counters on it.
Crystalline Crawler does not have summoning sickness and cannot be blocked and killed by an opponent.
Steps
Declare
Crystalline Crawler as an attacker.
Byrke's second ability triggers, doubling the number of +1/+1 counters on
Crystalline Crawler.
Move to your postcombat main phase.
Activate
Crystalline Crawler's first ability five times by removing five +1/+1 counters from it, 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 phase after this one.
Repeat.
If
Crystalline Crawler has at least six +1/+1 counters on it, this combo nets infinite +1/+1 counter doubling.
Results
Infinite colored mana.
Infinite combat phases.
Infinite untap of creatures you control.
Infinite mana creatures you control can produce.
Infinite +1/+1 counters on creatures you control that have a +1/+1 counter on them.