You need three or more opponents for this combo to work.
When Tivit enters the battlefield, each player will be given the choice between allowing you to create a Treasure or a Clue token
Academy Manufactor will make you, regardless of choice, create four Food, Clue and Treasure tokens
Sacrifice Tivit, and pay four mana to return him to the battlefield with Nim Deathmantle
Repeat the process.