Brandon=average. Who did he kill? anyone impressive, with a powerful history? For all we know he could have killed a bunch of padawans. Perhaps he stood out in comparison with sion, but was sion a walking corpse unable to die yet? Other then the feat of being invincible, sion shows very little in pure power even at the time of kotor II, and more in saber skills/invisibility. In the cannon version of Kotor, nobody else even gets a chance to try and rule the star forge aside from malak and revan, as republic ships destroy the star forge as soon as malak is dead.