The Monk is a cross between a Paladin, Assassin, and Barbarian. You roll is basically a tank or off/tank. With this said, you can go two routes. The solo tank build with a dps companion will require you to maximize defensive passives and focus on drawing and managing enemies. You won't be able to "draw all the aggro" and sit or you will die on the harder settings.
There are a few sites that have build strategies for end Monks; just google.
I wouldn't go for the dps rout because there are other classes which perform this task better.
You may also want to practice building a team oriented monk. This way when you want to get better loot or have some fun on social games, your teammates will like to have you around.