Varina, Lich Queen [Best Aggressive Card Filtering and Token Burst] Varina, Lich Queen rewards attacking with Zombies by turning combat into card selection, lifegain, and graveyard setup all at once
An example of a card effect you might not want to use but must would be Merlin Crab
Then, at the start of your end step, you get to bring back a creature from your graveyard back to the battlefield, so long as its power is less than Mirkos
This is ideal for anyone who is thinking of playing Standard because less viable sets mean there are fewer cards you have to chase after in order to play
Like most other creature spells, Hook-Haunt Drifter can be responded to, countered, and the like
Other cards even other TMNT cards you have bought or won at the prerelease cannot be added to your deck during the event