Shugoki
Batter up! The big bad of the Samurai lineup is the Shugoki, a plus-size purveyour of damage on the largest of scales. While similar to the Lawbringer in many ways, the Shugoki is a little better for beginners- his Uninterruptible Stance means that getting hit while executing Light Attacks won't faze or stop him, making him a little less of a pincushion for those lightning fast Peacekeepers.
Unfortunately, Shugoki's charging attack is one of the game's least intimidating- it's an automatic knockdown if it connects, but it can be tricky to capitalize on, as you have little control over where the body ends up. Be sure to cancel with [E] as soon as you've hit yout target.
It is useful for giving your teammates an advantage in a particularly thick Dominion or Deathmatch melee, though, and is tailor made for knocking poeple off narrow bridges. You might also use it to catch up to fleeing enemies who think they're safely out of your range.
Those situations aside, you're better off letting enemies come to you. You have a decent range, and you do damage even on a block. Combined with a Lawbringeresque low-throw manuever, no one should be able to get close to you unscathed. Shugoki is the rare class where Parries aren't always worth it. Your club is slow, and can be difficult to time. It's also easy to hold the button a moment too long, entering a powering-up state rather than a parry. You should still parry when feasible, to open up the enemy for your heavy attacks, but you can get by just fine using regular blocks and your light attacks.