>>212811675 (OP)Nyle sacrifices his entire life to this cult, volunteering himself for a ritual to "bring back the motherload" when he was younger. In return he got nothing. His spiritual mentor became a decrepit, senile man with nothing to his name. No family, no fruits for his labor. When Nyle sees the state Arboria is in and thinks back to what he went through-- how he was stripped of his humanity, how he saw hell, how he touched God and was punished for it he decides to say FUCK IT and accepts himself as a monster. His boss is dead, he hates his wife, he's not satisfied with the Elena research so fuck it. He stops taking his medication, stops pretending to be human by revealing his deformities and has the singular goal of destroying the only thing with power over him, Elena. She went through the same ritual but remains pure-of-heart, she wasn't traumatized in the same way because she was but a newborn. Elena also came out of the ritual with far stronger psychic powers than Nyle. He feels like she's just too pure for the power she holds to continue existing. She has a physical and mental chokehold over him (rent free). At the end of the film he finds two teenagers who he believes to have raped Elena "you fucked her" and it infuriates him not because he cares about the girl, but because he views it as another power move over HIM. It's removing HIS agency, HE wants to kill her, HE wants her to be pure so HE can take it. It's completely unbridled vengeance. In the end, Barry Nyle dies because of that lack of restraint. Elena simply uses her psychic powers to suspend his ankles, but he tries moving towards her anyway and this causes him to trip.
It's a character study on Barry, rewatch the movie think about it through that lens. You don't have poor taste for finding it boring initially, just gotta work to dig into what it's trying to say. Watch Mandy too, by the same director and has similar themes in a more digestible script