[If this being’s evident unfamiliarity and suspicion regarding Liem had been one hint, the total ignorance about the process of exchanging energies for the ritual confirms his suspicions. If Byleth’s mysterious hitchhiker has any awareness whatsoever of what he did before they took control of his body, it cannot have been vary precise. The gaps in their knowledge are simply too large for anything else to be true — and given that, Liem suspects that this being might not know anything about him at all, including the faction he previously belonged to.]

It is a simple ritual. The crystals embedded in our bodies must be revealed, and then anointed with each other’s blood. Then, the energies in them can be exchanged: light for dark, dark for light.