He's on the top of Van Medoh. The fight constitutes of two parts:
The first phase of the fight is quite simple. The opponent will float above the ground, shoot with lasers from his cannon and summon a tornado. Try to run and keep a safe distance all the time. It's most sensible to put the fight at a long distance - in the arena you'll find a window that you can use to soar with the Paraglider. The time slowdown will allow you to shoot a few fine shots. A good solution is to use exploding shots, which deal a lot of damage. If you want, you can also deflect your enemy laser with the help of a shield, as with Guardians, although it requires good timing. Stage two commences after the boss loses more than 50% of health.
The boss will summon four minions that will aid him in the fight. The attacks of this boss will be slightly changed. He'll be summoning a couple tornadoes instead of just one, and the laser beams will bounce off the flying things, and will be harder to avoid. The boss will also sometimes charge from above, so keep your distance. Your strategy won't change, though. Aim for the boss' eye. Accurate shots will briefly stun him, giving you time for additional attacks. Keep to the geyser, hover and try to aim well, and you should win quickly.