oneself
Arcane
On a different note,
Given that Johnny taking over is a Theseus' ship sort of situation, wouldn't it be possible that letting Johnny take over the body would nonetheless mean that V's stream of consciousness is preserved? Johnny himself (and Victor) mentioned early on that your two personalities were becoming intertwined, so giving him your body seems more to be the case of a person with multiple personality disorder discarding his original personality in favor of the second one.
I don't believe it is a Theseus ship situation. The final stage seems pretty abrupt.