Its a totally cool and unique design, but its also pretty bad
None of the cards can be considered for cube, since for the few cubes that do have a shard section there are better options in Jund like [card]Hellkite Overlord[/card] ([card]Reanimate[/card]/[card]Natural Order[/card] target) and [card]Broodmate Dragon[/card] (value), though Prossh may synergize better with a list supporting a sacrifice theme
If your choice somehow ends up with an instant or sorcery card as the back face of Werewhat, Werewhat would be unable to transform away from its daybound side, so it would remain daybound even if it's night
Youll see some of the basic Pokmons like Squirtle, Sandshrew, and others replace specific Tetramons
Notably for the Commander players, these abilities trigger when any player attacks with multiple creatures, so its a great card alongside goad
The goal is to maximize your artifact production to get to at least eight artifacts of the same name and win with this aura attached to one of them