Some articles on unizon:

Zoids Saga III: Fuzors
... One of the major changes made to the game was the way Unizon Zoids were formed ... When Unizon Zoids were introduced in Zoids Saga II the player had to have all of the Unizon Zoids in a certain formation and use a deck command to fuse them ... Each Unizon Zoid was fused for the entire battle and only got one attack per turn cycle ...