Lord Knight. Paladins are meh and usually mediocre, whether in LR, MR, HR, and SHR. Lord Knights have the largest HP multiplier, Atk Modifiers, and a bunch of other stuff. Paladins are easy to play (since I forte Swordsman classes), but limits the true abilities of the swordsman class.
Lord Knights are challenging, sometimes overpowering if you know how to play them.