In X6 for PSX you could get Black Zero by beating Nightmare Zero when he was level 4. However, due to a design oversight this was not possible. Is this glitched fixed in X Collection, because if it is then u can have Black Zero and Ultimate X on the same file?

I don't see how its possible. To my knowledge, you can't fight Nightmare Zero once Gate's Lab is open, and the lab opens automatically once you gain 3,000 souls. Since you need to be at PA rank, which requires 5,000 souls to even fight Level 4 bosses, I don't see how its possible to fight a Level 4 Nightmare Zero.

You can get Black Zero in X6, but if you want Ultimate X then you have to put him in a different file.

In X5 you can have both Black Zero & Ultimate X... that is if the Laser or the shuttle destroys the colony. If not than Zero gets taken away. In X5 I usually go with Ultimate X, because if Zero is gone then you're left with the weak X.

In X6 you put in Code for black Zero.

I think KingofWei already knows that he was just asking if you couls have Black Zero and Ultimate X on the same file.

well in that case yes you can

How do you do that?

put in bolth codes you get at the end of the game

what are the codes?