Unfortunately, Necroduality is so popular and printed in limited numbers that it can be tricky for Zombie fans to find one without sacrificing their firstborn
However, its not impossible either
Tashas goals are straightforward: cast spells you dont own and create a 3/3 black Demon token each time you do with Tashas static ability
Red offers discard outlets like Faithless Looting and powerful cards like Sneak Attack if theyre in the Cube, green offers Survival of the Fittest to go with Recurring Nightmare for the classic Rec Sur archetype, and white offers Unburial Rites as well as the ability to cast some unbeatable monsters like Elesh Norn, Grand Cenobite
Tannuk, Steadfast Second has a familiar Sneak Attack-like ability, not unlike Purphoros, Bronze-Blooded, and it should get people brewing around massive artifacts and red creatures
You might have noticed that the cards in the list above don't really do anything synergistic together