Selvala, Heart of the Wilds does not have summoning sickness.
Notable Prerequisites
You have a way to give
Selvala vigilance.
You control a creature with power 6 or greater.
Mana Needed
({G} magic symbol) available.
Steps
Declare
Selvala as an attacker.
Holding priority, activate
Selvala by paying ({G} magic symbol) and tapping it, adding at least ({W} magic symbol) ({U} magic symbol) ({B} magic symbol) ({R} magic symbol) ({G} 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 from step 2.
Results
Infinite colored mana.
Infinite combat phases.
Metadata
In 3582 decks according to EDHREC.
Bracket Tag
This combo has been estimated to be Spicy (Bracket 3-4+).