PresidentOfJelybeans

Well, first an easy way to avoid getting hit is to make sure the circle in the middle will be between you and Nefarious, so when he does that blue shadow thing, he won't be able to hit you, but when he throws the grenade thing, be sure to jump up out of the way. And when he uses the grenade, try hitting him with the wrench directly after each time you jump, so as not to waste ammo. After you beat him just use weapons you won't need later to kill the enemies in your way on the way to fighting Nefarious again. When you've got to the next Nefarious fight, follow the same strategy with the grenades he uses, but be sure to use your long jump to avoid being hit by his shadow thing. When he jumps in the air to do his laser thing, just focus on getting out of the way of the beam. If you get a chance, you can try to shoot him with the flux rifle, or the Annihilator. Do your best not to run out of ammo, so use your weapons wisely. It may take a while, but you can eventually beat him by following this strategy. Then you have to fight the biobliterator, but it's really easy. Just keep shooting at it in the hovership.

Then you're done!