To either revive or kill something

Solution 1:

Probably Romans 7:9 and the surrounding verses probably have the clearest references to toggling aliveness: "I was once alive apart from the law, but when the commandment came, sin came alive and I died." Since this venerable reference has no better term for it, I have to imagine that there is none.

Looking up "to hover between life and death," I found "terminal state," which may serve for "life/death status."

Is "trans-" the closest prefix to the meaning "switch" or "toggle"?

Perhaps you should coin a term?

I togglived ("toggle-lived") him.

or:

He gave me no choice, so I trans-slew him.

Solution 2:

While I am not aware of a term that describes the switch between alive and dead, aliveness describes life/death status

the quality of being alive

It appears to have an increasing usage in both British and American English.