Because life can get complicated for characters in SA, there are certain rules regarding what does and doesn’t count as "your character."
The Rule of Intent
If something happens to your character as an intentional result of your character’s actions, you control the resulting character. If you run a Persona Lens, walk into a replicator, have a frontal lobotomy, or even kill yourself so you can be resurrected later, you still play the resulting character even if one could argue that it “isn’t still you.” The guiding principle at work is that characters are defined by their choices.
The Rule of Force
In the case of drastic changes to your character that your character would have opposed, knowing the outcome, you or the GM may decide that you no longer control the resulting character. If you get forcibly cloned, shot and killed, mesh-hacked and enslaved, brainwashed, etc. into something your old character wouldn’t have agreed with, the default is that it’s time to pick up a new character – the old one is now an NPC. You and the GM can talk about it if you still want to play the resulting character. If either one of you says “no,” then it’s time to make a new one.
The Rule of Identity
All versions and instances of your character are still yours to control unless the Rule of Force comes into play. If you intentionally made 100 copies of yourself, you have authority over all of them. If someone made a clone of you without your knowledge, things would depends on whether your character would appreciate that or not, as per the Rule of Force.
The Rule of Reversals
If the drastic changes mentioned in the Rule of Force are substantially reversed, you may, at your option, regain control of your character.
The Rule of Ontological Inertia
If a character leaves play, permanently or temporarily, the player can still activate Themes from the character until the player receives a new character or the old one returns to play. This primarily applies to dead or unconscious characters. Such characters are unlikely to garner Twists, so playing a permanently dead character limits one’s options.