I started looking at this deck back in Feburary, but it was always a little weird to me. I like decks that are open ended and not necissarily archetype locked, this is that to a T. The branded cards are a sort of toolbox to make a more diverse endboard that can change per matchup, the bystials can interupt fiendsmith, and the acrhfiend can grab Simul archfiend and turn off decks like White Forest, Tenpai, Gimmick Puppet, and even Snake-eyes.
Obviously, cards like nightmare apprentice and Diabellze are great. Diabellze is a floodgate and adds to a layered endboard and nightmare apprentice adds so much to the consistency of the deck, but they are kinda too pricy for me, especially nightmare apprentice.
I had added a few packages to the deck to diversify it. I think this is neat because different decks lose to different things and having access to a diverse extra and thus a diverse end board is very important, but branded already does that, right? Kinda. It adds a new starter, end board pieces, and hand trap bait, but I found cards like Magnum wouldn't be summoned out because I had to use my fusion cards on more powerful cards and if I only had access to another poly I could do more and raise the ceiling of my endboard. So I just added a Fluffal engine to get to Poly. I may tweak the numbers on it, but I generally feel that this deck doesn't mind drawing Poly too much. It sucks if you can't dump a Coatl into the grave, but it's not the end of the world so long as you can make it to turn 3.
I am also looking into a melodius engine which is why it is in the side deck. I would probably side the super poly, bystials or the archfiend stuff depending on going second and the matchup. I think setting super poly is never really a bad thing in this deck, though it opens the deck up to back row hate considering you generally want to lay down your chimera fusion on your opponent's turn.
Overall, I think the deck is in a good spot right now, I'm playing around with different Illusions I can summon off of Tao and the Melodius variant. This can be optimized more, but until I find 100$ to drop on a playset of nightmare apprentices (or they get reprinted in not secret) I will probably roll with this version. I will add Diabellze later when/if I get one.