During early closed beta, Devil Dinosaur cost 3 mana and was one of the cards that completely dictated the meta. At that time, Moongirl was a 3/3 and was also in every deck. The cards run in tandem could often be a part of devastating turn 6 plays that added an obscene amount of power to the board.
This basic premise of this deck is that by using Sera, the powerful turn 6 plays involving these cards are once again back on the table. Quinjet is also in the deck, meaning and cards you duplicate with the Moongirl potentially become insanely cheap.
With Sera out, on turn 6 you can play 2 Devil Dinosaurs if you previous duplicated them with Moongirl.
Or, you could play Devil Dinosaur followed by Moongirl, to fill your hand and buff Collector.
I have been having success with this deck at infinite rank.
Outside of Sera, Moongirl, Devil Dinosaur, and Collector, the rest of the deck is somewhat flexible. You should be looking to run at least 1-3 cards like Cable and Sentinel that fill your hand. Outside of that, there is room to substitute nearly any other card you want, be it something like Shang Chi, Daredevil, Goblins, Scarlet Witch, Iron Man, Beast and a bounce package, etc. The decklist here shows some choices I've used that stick to the theme of handsize, but you don't really need this much draw.