If you're up for challenge, go for Warrior. Warrior got a lot of fight mechanics you can use than Paladin, way more.
Paladin is a simple straight-forward tank. You just need to click 1>2>3 and sometimes Shield Wipe or Riot Blade for mp which you might not need. That's all.

However, most of the end game fight prefer Paladin as MT because they got better damage mitigation and Hallowed Ground.