Gyromancer

The Dragon Lord is at the far north end of Dragon's Haven, you can reach it fairly easily by moving up the right hand side, with only a minimum of encounters. I recommend using a Wyvern in breakthrough to start out the fight, as matching red gems will give you a bonus while giving him nothing. Above all else you want to keep his ability gems out of play when it comes time for his Time Twist (reduces countdown gems to 1).