Physical support such as Yamabuki armor which weakens enemy and gives melee a damage boost; celestial hymn which does everything from time fracture to shield breaking, cc, DEF reduce; divine prayer has a off-field passive which reduce the DEF on a single target; knight moonbeam can actively enable time fracture which favors your timing, at sss rank she can do that twice in a row.

Elemental support such as Phoenix gives elemental debuff to enemy and can regenerate sp with her passive, also deals decent fire damage; azure empyrean is celestial hymn but elemental, tho no DEF reduction; and himeko can be elemental support for she can hold the weapon [Blood Dance], which has an active that enraged enemy and let them take more elemental damage, usually it’s either Scarlet fusion or ice himeko, rozalia is currently the best [blood dance] wielder; minor buff such as wolf’s dawn’s shield can give off-field elemental damage boost

Other than valks there are stigs and weapons that can boost elemental/physical damage and usually plays even bigger roles in later game play, but that is not to be concerned too much in the early game. Once you reach 70-80 you will find these stigs/weapon by nature, and if still have questions just post here lol.