Activate Tyvar by paying {3}{G}{G}, giving creatures you control at least +5/+5 until end of turn.
Activate Devoted Druid's first ability by tapping it, adding {G}.
Activate Devoted Druid's second ability by putting a -1/-1 counter on it, untapping it.
Repeat from step 2 four additional times.
Repeat from step 1.

Infinite green mana

Infinite power and toughness for creatures you control until end of turn

Tyvar, the Pummeler

Devoted Druid

At the beginning of your upkeep, Mayael's Aria triggers.
Holding priority, activate Tyvar by paying {3}{G}{G}, giving creatures you control +X/+X until end of turn, where X is the greatest power among creatures you control.
If you do not control a creature with power 19 or greater, repeat from step 2.
Resolve the Mayael's Aria trigger, causing you to put a +1/+1 counter on each creature you control, gain 10 life and win the game.

Combos with "Tyvar, the Pummeler"