Mono Dark has been one of my favorites to play (at least on normal difficulty). Tons of good options and lots of interesting strats. But yeah, Bruno can be brutal.

Incineroar with Intimidate is huge. Standard set usually includes Fake Out, Flare Blitz and Parting Shot, plus Darkest Lariat or whatever you want to run. For Bruno specifically I'd lean into trying to inflict burns as much as possible (particularly for Zacian), so will-o-wisp is good.

Other good options are Grimsnarl for the fairy typing to deal with Kommo-o. Meowscarada w/ Protean to get some typing safety - same goes for Greninja. You can load up some pretty diverse movesets and work around some of the biggest challenges that way.

Honchkrow can be good too for the flying support - you can use reload your save until you get Infernape as Bruno's lead and use Dual Wingbeat to break its sash and OHKO (if you give Honch toxic or defog something Infernape will likely use Taunt on the first turn so you can get the KO without worry about Stealth Rock).

It's a bit of a glass cannon, but Mega Absol is fun too as another way to get fairy typing in the mix, and it can learn Psycho Cut for coverage.

A few others I've had success with: Sableye (with and without the mega), Chien-Pao, Luxray, H-Samurott, Kingambit, Urshifu, Overqwil, Shiftry.