Crystalline Crawler has at least seven +1/+1 counters on it.
Crystalline Crawler does not have summoning sickness.
Crystalline Crawler and
Hellkite Charger cannot be blocked and killed by an opponent.
Steps
Declare
Crystalline Crawler and
Hellkite Charger as attackers.
Byrke's second ability and
Hellkite Charger trigger.
Resolve the
Byrke trigger, doubling the number of +1/+1 counters on
Crystalline Crawler.
Holding priority, activate
Crystalline Crawler's first ability seven times by removing seven +1/+1 counters from it, adding ({5} magic symbol) ({R} magic symbol) ({R} magic symbol) .
Resolve the
Hellkite Charger trigger, causing you to pay ({5} magic symbol) ({R} magic symbol) ({R} magic symbol) to untap all attacking creatures you control and to get an additional combat phase after this one.
Repeat each combat phase.
If
Crystalline Crawler has at least eight +1/+1 counters on it, this combo nets infinite +1/+1 counter doubling.
Results
Infinite colored mana.
Infinite combat phases.
Infinite +1/+1 counters on creatures you control that have a +1/+1 counter on them.