I think the major reason was that the dhelmise let you ohko kirlia with registeel, and I think that is why most of the people start to play psychic kirlia now. And it can help math in some other situations. I feel like it is just a little interesting inclusion in the deck.I think that the Oranguru should stay for late game draw support, so maybe remove one of the Acerola instead? I've never tested this deck, so I'm not completely sure why the Dhelmise is in there in the first place (I suggested mainly because that is what I've heard was played in this deck). What math is it trying to hit in the first place? I have some experience with Metagross GX, and I used to play Dhelmise but it never really helped me with anything since 190 wasn't really a problem (since I could hit them with Beldum for 20 to get that math).