I haven't had much success w/ any of the Choiced sets like CB or Specs (though they have been effective against me), but Sub DD is really really good, esp under screens. This Pokemon can setup all over a lot of Pokemon like Garganacl since it can't break its sub w/ Salt Cure (under screens Salt Cure 4HKOes the sub) and then go to town from there. Tera Blast is really good STAB, but I've also been surprised by how solid Dragon Darts is now. With all the Bulky Fairy-Types like Clefable and Tapu Fini gone, Dragon Darts has far fewer immunities now compared to before, barring some Tera Fairy Pokemon, so you don't even need to terastalize Dragapult in some MUs and just spam Dragon Darts to get the KO you need. In MUs where you do need to Tera Dragapult, Tera Ghost will get the job done just fine, as Hatterene is weak to the move and most Iron Valiant don't invest into bulk, so they just get dropped. at +1 and a wee bit of chip damage. Grimmsnarl is an annoying MU, but Dragapult's partners like Chi-Yu and Gholdengo can take advantage of Grimmsnarl to setup & deal big damage.