Lets make Zerg a fun race again!
Change the infestor into an INFESTOR
Neural parasite can work on Buildings that have been corrupted.
While corrupted as usual buildings no longer can make units. HOWEVER if an infestor, Infests a building thats been corrupted it will produce units like normal for the enemy. Hidden inside is a parasitic worm that will turn the unit against the enemy for 30 seconds. After 30 seconds the unit explodes from a heart attack and dies.
This only works on Biological units and not massive units so as to leave a function for neural parasite.
You can maybe make the parasite work on regular units too and make it cost like 25 energy or 50 energy or something. Something like spawn broodlings did in Brood War.