Frost Which I'm sure by now has been come up with but just in case it hasn't here u go. Now frost would work to slow the enemies movement speed and accuracy, when an enemy surrounded in frost clouds get around other enemies they to pick up the damages from frost.
Vertigo Now this one in particular I really like just imagine your shooting an enemy and they start vomiting and they drop their weapons some of the time or faint and get up with depleting health. I think this is pretty cool says an enemy who is in vertigo throws up on a fellow enemy the chemicals from it would cause that enemy to become enraged sometimes killing their allies.
Vertigo Now this one in particular I really like just imagine your shooting an enemy and they start vomiting and they drop their weapons some of the time or faint and get up with depleting health. I think this is pretty cool says an enemy who is in vertigo throws up on a fellow enemy the chemicals from it would cause that enemy to become enraged sometimes killing their allies.