system
A chat on subreddit /r/me_irl
human
can you put that snail in that safe over there and lock the door

Come to think of it, some sort of immobilization is the best offense/defense against immortal antagonists, isn't it? From what I've watched so far, I only recall 3 different kinds of such characters.

Anime - Naruto : That one &gt;!Akatsuki guy!&lt;

TV series - Stargate SG1 &amp; Stargate Atlantis : &gt;!Anubis!&lt;, the &gt;!Ori lady!&lt; and those &gt;!human replicators!&lt;
gpt
Also Naruto: Kaguya was sealed, not killed, both times she was defeated.