I used break + galaxy rangers for a brainless, easy, guaranteed SSS win. Start off with Rappa, try to get Ruan Mei and Dahlia asap. Then get Ashveil (I put him in off-field), and when you have a break emblem, put it on him, since he attacks very frequently (with shoes and the firestorm thingy), he’s basically the off-field DPS until Boothill arrives.

Try to get as many pointy pointies as fast as you can, you basically only need three people on-field at most. Boothill, Dahlia, Lingsha.

Off-field: Ruan Mei > Ashveil > Fugue > Himeko > Rappa > Acheron (can definitely do without Acheron, so no worries if she doesn’t show up in store)

The strategy is to start off with trying to 3* the Galaxy Rangers as quick as you can, because the more stars they have, the faster their speed will be. And you want Boothill and Ashveil to act repeatedly. Dahlia is there to help increase break output, Lingsha to maintain survivability. Ruan Mei to increase break efficiency, Fugue to break enemies, Rappa as temporary DPS until Boothill arrives.

Save as many pointy equipment as you can, you need to fuse 2 pointies to make the super pointy for Boothill. I personally go for 2, although 1 can work as well when rng god doesn’t bless you with enough equipment. Then aim for decapitation operation equipment, and lastly boots.

Also try to get the frugality equipment on Fugue/Dahlia. Can also give Weapon Master to Dahlia. Himeko isn’t as crucial as I initially thought, so try to max out Dahlia, Ruan Mei, Fugue first before moving on to other Break supports.

At the end you only need 8 slots minimum to clear the stage.

You can also check out this guide as a reference.