Xiao’s talents: Bane of All Evil -> Whirlwind Thrust -> Lemniscatic Wind Cycling
Xiao uses Prosperity books and slime components to level-up his talents.
Personally, I don’t think his elemental skill, “Lemniscatic Wind Cycling,” should be a priority. You’re more likely to use it just to gain elemental orbs (each successful dash attack generates three particles).
Note 1: If you’re using Xiao’s elemental skill to charge his ult, my suggestion would be to cast it at intervals. The dash attack’s animation is blindingly fast that you might also end up missing if you cast it twice in quick succession.
Note 2: Although Xiao’s elemental skill generates particles when he’s in his regular form, it won’t spawn particles if used while his burst is active. Outside of getting kills for a few measly orbs, you’d be back down to zero after your burst’s DPS routine. I’m not sure if this is a bug or if it’s working as intended.
Anyway, the important thing here is Xiao’s burst/ult known as “Bane of All Evil.” It should be your go-to ability once it’s available. It converts all of Xiao’s damage into Anemo while increasing his attack’s DPS and AoE.
Now, the tooltip might say that the effects end once Xiao leaves the field, but the whole thing also lasts for roughly 14 seconds. Likewise, Xiao loses a bit of HP while the effect is active, but leveling the talent lowers the percentage of HP that’s lost. Leveling also provides increases to your normal, charging, and plunging attacks. In general, you’d be jumping and spamming plunging attacks while the burst is ongoing. Try to reach the maximum height of his jump prior to plunging (the high plunge attack from maximum height has a higher coefficient than the low plunge attack).
Note: Long story short, you’ll want to level-up Xiao’s “Bane of All Evil” followed by “Whirlwind Thrust” (since this also boosts plunging attack damage). Don’t bother with “Lemniscatic Wind Cycling” unless you have a lot of resources.
Okay, the next part of our guide talks about Xiao’s character ascension materials found all over Genshin Impact‘s world map.