Crystalline Crawler has power 5 or greater, does not have summoning sickness, and cannot be blocked and killed by an opponent.
Steps
Declare
Crystalline Crawler as an attacker, along with any number of Warrior(s) if desired.
If you declared one or more Warrior(s) as attackers,
Najeela triggers, creating that many 1/1 Warrior creature tokens that are tapped and attacking.
Deal combat damage using
Crystalline Crawler.
Quilled Greatwurm triggers, putting that many +1/+1 counters on
Crystalline Crawler.
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.
Results
Infinite ETB.
Infinite colored mana.
Infinite combat phases.
Infinite creature tokens with haste.
Infinite combat damage.
Infinite +1/+1 counters on a creature.
Metadata
In 0 decks according to EDHREC.
Bracket Tag
This combo has been estimated to be Exhibition (Bracket 1+).