Sharky Boshaw (Burn, Baby, Burn)
Find Sharky in the Moon Flower Trailer Park, north of the jail in Faith's region.
He'll be on the roof of the Bingo hall, doing his best Doof Warrior impression.
Speak with him to kick off his recruitment mission- Burn, Baby, Burn.
Angels will flood the site. If there's any weapon you've meaning to get more kills with, now is an ideal time to equip it. Explosives in particular are abundant here.
After you and your mates take out about twenty or so hostiles, Sharky will try to shut the speakers off, but fail. Follow the new plot markers to shut them down, as a new wave of Angels attacks. One switch is right by Sharky.
One is west of Sharky, on the ground. You'll have to come in from the north to get around the fencing.
One is on a knocked-down pole at the north side of the camp.
The last is up a tower at the trailer park entrance.
Note that, during all this, 'regular' cultists may also be drawn in by the hub-bub.
Once all the speakers are deactivated, kill any remaining hostiles.
Talk to Sharky again to unlock him as a companion, and complete the mission.
Note that Sharky is good for
many several things, but clean hunting kills are not among them.