This video might not show it, but Blacephalon is SIGNIFICANTLY STRONGER than both Megas, I could not complete this with with Blaziken nor Charizard as leads, I had to put Blacephalon first because if he can hit freely he will charge Mind blown with only 1 Incinerate + 1-2 Fast attacks from Genesect, which in practice means you charge 1 Mindblown every 1 Incinerate as you receive damage before you can move again.
I've found flamethrower genesect is the hardest move, and you might want to use Charizard there instead because it survives longer, but the best I've found is to simply take more blacephalons in, he really does output that much dps and tanking a flamethrower charges nearly 3 Mind Blowns.
TL;DR: THE CLOWN DOES BRING HUGE FIREPOWER!!!!!!!
by ComettYT