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 and Hellkite Charger as attackers.
Byrke's second ability triggers, doubling the number of +1/+1 counters on Crystalline Crawler.
Holding priority, activate Crystalline Crawler's first ability five times by removing five +1/+1 counters from it, adding ({W} magic symbol) ({U} magic symbol) ({B} magic symbol) ({R} magic symbol) ({G} magic symbol) .
Activate Najeela by paying ({W} magic symbol) ({U} magic symbol) ({B} magic symbol) ({R} magic symbol) ({G} magic symbol) , untapping all attacking creatures, giving them trample, lifelink and haste, and gaining an additional combat phase after this one.
Repeat each combat phase.
If Crystalline Crawler has at least six +1/+1 counters on it, this combo nets infinite +1/+1 counter doubling.
You may also attack with one or more Warriors each combat phase to gain 1/1 Warrior creature tokens from Najeela.
Results
Infinite ETB.
Infinite colored mana.
Infinite lifegain triggers.
Infinite lifegain.
Infinite combat phases.
Infinite creature tokens.
Infinite +1/+1 counters on creatures you control that have a +1/+1 counter on them.