ok, so i kinda screwed myself. im at the champion and im having a real ruff go. i would really like to beat him with what i have, i really dont want to go through the e4 again, but what i have is not great. i have a delta charizard, with dragon pulse, shadow ball, scratch, lunar cannon, and holding delta charizardite. then i have delta galade, with ice punch, thunder ounch, nuzzle, icicle crash, and holding a magnet. then i have delta luxray, with iron head, poison jab, earthquake, crunch, and holding leftovers. and finally i have mew with psychic, dazzling gleam, flamethrower, dark pulse, and holding a shell bell. the last two pokemon are junk i use for healing. it might sound impossible with only 4 real pokemon, but i got through the elite 4 with them, and i think i can get through the champion if they just had the right moveset and items.
I suggest giving the delta Christensen pulse of dark matter.
Charizard
Drop either lunar cannon or shadow ball, they have the exact same coverage. I’d go with sludge bomb instead. If you give D. Gallade earthquake it checks 3 of its 4 weaknesses. Give it a wide lens and you don’t have to worry about missing with icicle crash. D. Luxray runs really well as a trap setter, mine has toxic spikes for poison, Roar to abuse spikes, super fang for reliable hp drop, and protect for stall. You’ll have trouble with other steel, poison, maybe ground types but your other mons should be able to handle those just fine. (Also, air balloon works really well with luxray. Removes its 4x ground weakness)