The only properly bred fairy I had for a bit was Ribombee. With the release of the new dlc, I'm noticing dragons with second types good against my bug. I just bred a Rapidash, might be a tad on the frail side. Are there any that would be more fitting for this?
I love my steel types and all, but definitely DO NOT take Mawile. It is super weak to special moves, which sucks. And a lot of dragon types have special moves that aren't dragon type (flamethrower, hydro pump, etc), and it could get one shot.
I stick with my Alolan Ninetales, though I use it more as support if all 3 other people are real people and not NPCs (Snow Warning + Aurora Veil).
I like Primarina. It has great Special Attack so it deals devastating damage with both its regular moves as well as Max Moves. Otherwise the classic Zacian is always a strong choice, but its Play Rough can miss.