as much as i feel for rin given his terrible isolated cave life, i dont really blame huey at all. from huey’s perspective, rin and eiden are another iteration of him, same as how he is an iteration of the huey before him.
if its all him, then he has the… autonomy to [looks at my notes] send himself on a fantasy vacation (aka isekai himself aka set himself up with a different life) at all costs.
he just decided to do something he wanted. to fulfill his dream and allow his future iteration a life in a different world, he had to strip his future iteration of his initial wish and his magical knowledge. so he did that and then he fulfilled his wish and entered his Epic Coma Moment
sometimes, people abandon parts of themselves or get rid of parts to accomplish their goals. it feels a little cold, but it happens. i suppose huey could have killed the half of his future iteration cursed with a wish it would never fulfill, but it’s hard to picture him empathizing about a future iteration of his half-soul being lonely or longing. maybe if he thought of himself as a person, it would be different