Nothing more awesome than a Arch 3 Theseus that's 14 stars and has 91k skill atk being weaker than a Rhize that's Saint 2 with 9 stars, both having the same gear/runes.
KT's defensive gains far outweighs Rhize's.
At 18 stars, KT has the highest defensive bonuses for any hero.
That's why you see top players use KT in PvP, not Rhize.