Most attempts at a Contract deck have relied on Arcane Adaptation turning all of your creatures into Demons, and then winning that way
Let's see them in more detail: Straight Boltund VMAX Deck This list is built with a very linear idea in mind: use the power of Flaaffy to attach energies from the discard pile and start using Max Bolt as early as in turn 2
As a rule of thumb, Ive found that if the card(s) in question cannot win you the game outright, the answer is usually No. Cards like Insurrection, Finale of Devastation, Rise of the Dark Realms, Armageddon, and Expropriate are cards that often belong to this category, and should be added very sparingly to your deck
As an alternative for that, use Marie Favored Kitten or other strength buffing cards, then play Stabbington Brother Without a Patch to Rush in and take out must-remove characters
It looks powerful and ready to attack