Mayael's Aria and Devilish Valet on the battlefield.
Opponents control at least five creatures.
({2} magic symbol) ({W} magic symbol) , plus an additional ({1} magic symbol) ({W} magic symbol) for each opponent as needed available.
Steps
At the beginning of your upkeep, Mayael's Aria triggers.
Holding priority, cast Call the Coppercoats by paying ({2} magic symbol) ({W} magic symbol) , plus ({1} magic symbol) ({W} magic symbol) any number of times as necessary, targeting any opponent(s) who collectively control five or more creatures.
Resolve Call the Coppercoats, creating at least five 1/1 Human Soldier creature tokens.
When the Human Soldiers enter the battlefield, Devilish Valet triggers that many times, doubling its power that many times, causing its power to be at least 32 until end of turn.
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.