Split from the other thread, since it really wasn't a Q/A thread, it was more for the "other game makers" thing.

Anyway, with a ZOMBIE system (I have to use all caps, it's the law), the best way I can think of it is to make ZOMBIE a status effect. Then, the defective healing items add that status, which might halve defense or something (or double attack while draining HP; depends on what you want).

For the "killed by ZOMBIES = you become a ZOMBIE" question, it's probably best to set up a battle trigger in the M. Groups tab. Set the trigger to be something like "Hero Draco HP is between 0% and 0%" and the events to revive Draco, give 10% HP and the ZOMBIE status effect. (Of course, this will prevent you from losing entirely. You may want to only ZOMBIE someone when they hit 10% HP or something.)

Or, just set a switch like [xxxx:ZOMBIEfied Draco] within battle, and use a common event to set ZOMBIE status after the battle, based on whether or not the character is dead.

If you need somewhat more specific pseudocode, ask away.