You spin me right round, baby, right round Soul Harvesters are pretty tough as well, as they have some wicked combo moves, are invincible during a good portion of their attack, and love to warp in behind you when you are fighting them. Then ready your shield and begin again. Once you get the hang of the timing you should do well. Recruiter Join us. Work is happiness.
Recruiters are fun, although a pain in the butt as well.
They are totally invincible, so don't waste ammo attacking them. If you do fire on a Recruiter, he'll spawn in four or five Swarmers, so it's best just to let them fly around. They don't have any offensive attacks so they won't bother you, except to make you want to move on to the next area, heh.