Also one last nitpick, I recommend changing Hippowdon's EV spread to 248 HP / 252 SpD / 4 Spe Impish, this means you won't have to switch out of Hydreigon as it can't OHKO you with Specs Draco Meteor and without this change you basically accept an automatic loss against it. OTR Rank does 56.1% max with Psychic easily letting you phaze it or just stall it out if you trust the RNG not to crit / SpD drop you. This fits better in your team IMO because Hippowdon's role is early game setting up rocks and phazing mostly, you don't rely on it to take boosted hits from Lucario and Terrakion because they won't be setting up on anything and can be revenged well enough if needed. I took mostly special hits with Hippowdon and as an example of how valuable this was I was taking 40% from Virizion's Giga Drain, easily preventing this otherwise massive threat from setting it up. I think this will help you a lot, good luck again!