Summoner + Eidolon + Essence Prism. What happens?

[Moppy]

This is an artifact in the GMG.

https://2e.aonprd.com/Equipment.aspx?ID=612

Activate 1 minute (Interact)

Requirements The prism has only one input stream, and a creature is encased in magic in the input stream

Effect Over the course of the next hour, the creature in the input stream has its essences refracted through the prism, creating two cocoons of magic in the output streams that each contain a new creature. At the end of the process, the original creature is gone, and the two new creatures break free of their cocoons. Each creature is part of the original, separated from the rest based on the last quality set by the prism’s first activation. For instance, if you set the prism to “good,” one creature would have all the original creature’s good aspects and the other would be the original creature’s evil side. Unless you selected a physical quality, both new creatures look just like the original. The new creatures are usually 2 levels lower than the original, but if the original creature was strongly biased with respect to the quality you chose (for instance, if splitting out the good and evil side of a redeemer), the stronger creature is 1 level lower and the weaker creature is 3 or more levels lower. If calibrated correctly, this activation can also reverse the effect of the third activation.

[David knott 242]

If you are using it to separate eidolon from summoner, my best guess is that you would have an unfettered eidolon (details TBD, to be converted from PF1) and a nerfed summoner whose Manifest Eidolon ability no longer works.

[Alchemic_Genius]

Since it's an artifact with a really subjective effect, it feels off to try an ask for an official ruling. Artifacts are, on the whole, plot devices more than anything else.

Since you have any number of possibilities here based on how you set the prism to split, it's impossible to provide meaningful feedback without an idea of how you're looking to split them

[graystone]

"ask you DM".

[BishopMcQ]

From a story standpoint, separating the eidolon from the summoner feels a lot like the story from the His Dark Materials trilogy.