A New Type of Immortality?

I may be wrong, but I was reading the Immortality part of Tv-tropes (https://tvtropes.org/pmwiki/pmwiki.php/Main/Immortality) looking for the type of immortality I was searching for. I didn't think I was completely original in my idea, but I'm asking you guys if this falls under one of these categories, or..well, I don't know. Anyway, the plot I use boils down to this; Guy A conceives an elixir. Guy B and C drink it along with A. This elixir merges the lifeforce of all three characters together. Therefore, when Guy B dies for instance, Guy A and C have some of their lifeforce torn away from them, and it eventually resurrects Guy B (Repeated killing of Guy B would eventually weaken A and C to a vegetative point, continuance of such would mean death, unless there is a long time span between deaths so lifeforce can regenerate.) Sorry if I'm rambling/sound like an imbecile here. First time using the T Vtropes forums.

(A member of a different forum directed me here, so I'm wondering if you guys have any answers. :3)

Seems like a mix of resurrective immortality combined with mutually vampiric and external immortality. It sounds fairly sui generis, but if I had to categorize it among existing approaches, that would be it.