>>34097769>252 Atk Necrozma Photon Geyser vs. 0 HP / 0 Def Rayquaza-Mega: 198-234 (56.4 - 66.6%) -- guaranteed 2HKO>252 Atk Necrozma Sunsteel Strike vs. 0 HP / 0 Def Rayquaza-Mega: 132-156 (37.6 - 44.4%) -- guaranteed 3HKO>252 Atk Necrozma Stone Edge vs. 0 HP / 0 Def Rayquaza-Mega in Strong Winds: 132-156 (37.6 - 44.4%) -- guaranteed 3HKO>252 SpA Necrozma Photon Geyser (Special) vs. 0 HP / 4 SpD Rayquaza-Mega: 196-232 (55.8 - 66%) -- guaranteed 2HKO>252 SpA Necrozma Moongeist Beam vs. 0 HP / 4 SpD Rayquaza-Mega: 131-155 (37.3 - 44.1%) -- guaranteed 3HKO>252 SpA Necrozma Dark Pulse vs. 0 HP / 4 SpD Rayquaza-Mega: 105-124 (29.9 - 35.3%) -- 22.9% chance to 3HKOMost moves can't even KO and assuming Ultra Necro lives right after Fug hits with the Dragon Ascent, E-Speed secures the kill.
Then there's Outrage/Dragon Pulse but that's why you come packed with a Fairy. Plus there's other threats Ultra Necro needs to deal with that takes dragon moves off the table. Like Yvevalt and Steel types.
U-Necro is going to be a beast offensively but is still just shy of a few quirks to be AG.