PSA: Rhaast is not broken; his damage is normalized.

With 300 bonus AD Rhaast has something like 34%+39%+620. Rhaast will deal 73% of their max HP +820.

Shadow form will deal; Q: 660 (950) W: 620 (893) R: 680 Passive: +44% So Kayn will deal 2523 total damage (not counting the one auto he makes between Q and W)

What does this mean? It means that Rhaast will ALWAYS do similar amounts of damage no matter the enemy (as his goal states; If behind, he will always be useful and never dead weight... something assassins and divers struggle with unless they have easy CC like Vi and renekton) and Kayn will ALWAYS perform better against squishy enemies, like his goal states.

Its almost as if riot is using %HP damage as a damage normalizer and not a tank buster stat.... ya know... like they stated years ago.