Krayt takes force (shattering a stone floor, ragdolling Nihl, Talon, Maladi, and destroying Pillars, as well as TKing Celeste Morne (who sent Vader flying), and killing Vong and Rakghouls are all good power showings.
Sabers could go either way, Ulic has exceptional showings of speed (appearing in 2-3 places at once, dodging blaster bolts on a darkside nexus, weaving long trails of light on a darkside nexus) are good feats, but Krayt is possibly faster due to blitzing multiple IKS. Krayt was forcing Celeste Morne to draw heavily on Karness Muur to amp her when dueling him in (before his prime), was actively taunting her, and tooled Cade pretty badly in their final duel.
Ulic has of course fought evenly with Exar Kun before his prime, killed Warb Null on a darkside nexus, and fought force sensitives while severed from the force. Not sure who takes that area.
Krayt might win all out due to superior power though