1 - Hydreigon prefers Draco Meteor over Dragon Pulse. It outright OHKOes any unsuspecting sweepers and switch-ins who didn't invest in SPDEF, and even some invested ones. For example:
252+ SpA Life Orb Hydreigon Dragon Pulse vs. 236 HP / 176+ SpD Breloom: 208-246 (65 - 76.8%) -- guaranteed 2HKO after Poison Heal vs. 252+ SpA Life Orb Hydreigon Draco Meteor vs. 236 HP / 176+ SpD Breloom: 341-402 (106.5 - 125.6%) -- guaranteed OHKO
Furthermore, U-Turn mitigates the single downside of this move through a switch-core, maximizing the value of both.
2 - Your team suffers from a glaring weakness to fighting types, being specially vulnerable to the common offensive coverage of fighting-ice (which is often achieved through the common splashing of Ice Punch in most fighting type sweepers). Part of this is aggravated by Salamence, who is a particularly bad choice due to its nature of being a fodder-punishing sweeper (as a setup focused unit due to dragon dance) that requires intensive support, to which your team offers none. You already have a far more effective and powerful sweeper in Excadrill, that properly sinergizes with the rest of this composition. I'd recommend swapping Salamence for Jellicent, who should be capable of properly covering for both Fighting and Ice weaknesses, serving as a check and counter for the likes of Conkeldurr, Azumarill and many defensive threats such as Ferrothorn and Forretress who Jellicent can reliably outrun and cripple through taunt. It also imposes a more well-rounded threat to ground types, further solidifying your core by providing a safe switch should Excadrill and Magnezone fall into a check. 3 - Chople Berry should provide more consistency for Tyranitar, allowing Ttar a chance to survive and revenge kill the likes of Gengar and Alakazam (bc focus blast). A careful nature is therefore preferred.
