So I noticed my win rate went up with powerlocks when I started training fortitude. Is fortitude a universally good skill like conditioning or is it kinda niche to some builds?

I was first training fortitude for Power Locks that I am aware of. Conditioning is only skill that applies to everything. No one knows the exact builds, all speculative.

all right side stats add to a fighters "energy" (one of the factors in determining the winner). conditioning has an energy multiplier. i remember chief being surprised at high the multiplier was that mkick gave it and he toned it down some. some rights are also primary stats for a given build.