Board Thread:General Discussion/@comment-26225812-20150617180152/@comment-25926288-20150617180703

Zelena states that her life force fled her body and joined with the magic of her pendant (since it released) and she somehow regained human form......I don't know. Zelena herself probably doesn't know how.

I think of it like this. The Pendant amps up the power a bit and gives an auto-revival once.