Skyward Blade is the closest fit on the game's own numbers: Xingqiu's kit multiplies ATK, and a weapon is ranked here on whether its ascension stat and its passive act on that stat. Summit Shaper, Fleuve Cendre Ferryman and Absolution come next. No playtested ranking has been imported for Xingqiu, so this is arithmetic over the kit data rather than a damage measurement.
Run Heart of Depth on Xingqiu, with Nymph's Dream and Celestial Gift behind it. Main stats are ATK% sands, ATK% goblet, ATK% circlet. Roll substats in the order Energy Recharge > ATK% > CRIT Rate > CRIT DMG.
Talent priority is Elemental Burst > Elemental Skill > Normal Attack. The Elemental Burst costs 80 energy, which is what an Energy Recharge target has to clear.
The strongest team is Xiangling, Xingqiu, Kaedehara Kazuha and Bennett, built around Xingqiu: Hydro · Vaporize.