Kingdom Hearts II Drive Forms

First of all I´d like to that I´m sorry if this has already been asked.
A while ago I was wondering what would i do if I had the power to make a drive form for Sora... So if you had the power to created a costum drive form for Sora, with the power to fuse him with up to two characters in the game (it can be any character in the game), how would you do it?, how would it be? and what kind of powers would it have?

In my case i´d probably do a Fusion between Sora and Sephiroth, and it would be like the Final Form only that with inverted colors, (with a black suit and white graphics) and sora would have white hair and a grey skin colour. He would have a Keybalde that lookes like made out of steel and it would be a mix with a Katana and the Keybalde. Finaly his powers would be like the Final form´s power and the Anti Sora form.