Opponents collectively control at least nine creatures.
Steps
Activate
Gwenna by tapping it, adding ({G} magic symbol) ({G} magic symbol) that can only be spent to cast creature spells or to activate abilities of creatures.
Cast
Ghalta by paying ({G} magic symbol) ({G} magic symbol) .
Brinelin and
Gwenna trigger.
Resolve the
Brinelin trigger, returning
Primeval Protector from the battlefield to your hand.
Resolve the
Gwenna trigger, putting a +1/+1 counter on it and untapping it.
Activate
Gwenna by tapping it, adding ({G} magic symbol) ({G} magic symbol) that can only be spent to cast creature spells or to activate abilities of creatures.
Cast
Primeval Protector by paying at most ({1} magic symbol) ({G} magic symbol) .
Brinelin and
Gwenna trigger.
Resolve the
Brinelin trigger, returning
Ghalta from the battlefield to your hand.
Resolve the
Gwenna trigger, putting a +1/+1 counter on it and untapping it.
When
Primeval Protector enters, it triggers, putting a +1/+1 counter on each other creature you control.
Repeat.
Results
Infinite LTB.
Infinite ETB.
Infinite storm count.
Infinite colored mana that can only be spent to cast creature spells.
Infinite colored mana that can only be spent to activate abilities of creatures.