Hint: it's not R=U
and Laguna has not been said.
Unless Rabah wanted it has the answer because Takara confirmed me he only meant the dream.
Hint #2: I said Dream(S) with an S, so Sorceress knight is right.

Seifer third confrontation:
Squall: Are you going to continue with that knight thing?
Seifer: The Knight has retired. I'd rather consider myself as a young revolutionaire. I always had to do somthing BIG. This has always been my dream.

I can't go much more precise than that.