Struggling with Harmony [Hard]

Right now my team consists of:

Mega Delta Charizard
Dragon Dance/Dragon Pulse/Shadow Ball/Confuse Ray

Delta Roserade
Lovely Kiss/New Moon/Moonblast/Lunar Cannon

Excadrill
Metal Claw/Earthquake/Rock Slide/Rapid Spin

Delta Gardevoir
Calm Mind/Livewire/Ice Beam/Thunderbolt

Delta Ludicolo
Fake Out/Water Spout/Aura Sphere/Psyshock

Talonflame
Flame Charge/Me First/Roost/Acrobatics

All of my pokemon are around the level cap (55) and I havent taken the time to EV train them yet. Their IV’s are iffy (Charizards and Ludicolos are trash iirc)

What pokemon should I add to my team for fairy coverage? Could I beat the gym with the team I have now with a different moveset or strategy? I haven’t even come close, she always has 2-3 mons left.

I was thinking possibly replacing Ludicolo with Delta Haxorus temporarily, I caught the Axew in Miara Town

Ok well I beat her now XD. I replaced Ludicolo with Delta Haxorus and it worked out pretty well. Stuck on fifth gym now but I’m sure i’ll get it eventually