"You are no match to us!"; "Your end has come!"; "This is where your path will end!".
Dark Monks will fight to the death.
Be careful. They often appear in groups or with other creatures so you may find yourself surrounded quickly. A level 97 knight or level 38 paladin will have enough mana to convince these to train with on Open PvP worlds.
Practice caution. Running into a spawn can get you easily surrounded. Move slowly and lure monsters out at a time to keep things easy. When you're comfortable with the spawn you can use a Great Fireball rune a couple times. GFB is also a good way to free yourself from a swarm. They heal like regular Monks so act quickly or you will end up wasting a lot of runes or mana.