The Lord of Darkness
Will-o-wisp is a status move do it won't change into G-max WildfireGengar just learned will-o-wisp, so, can it use g-max wildfrire when g-maxing? It would be like charm against Steven.
But, if it's a 3 vs 3, we still don't know what will be the their third. For Ash, I'd guess sirfetch'd, Steven, I dunno.