PSA #1:

DPS are the main protagonists. Absolutely awful at everything other than getting hurt and doing a lot of damage.

PSA #2:

Both Xiao’s abilities scale off ATK and OH BOY does he scale well. No wonder he’s always in agony, boy is literally falling headfirst into the concrete repeatedly.

E = Elemental Skill = Lemniscatic Wind Cycling

Q = Elemental Burst = Bane of All Evil

E - Lemniscatic Wind Cycling

Xiao lunges forward, dealing Anemo DMG to opponents in his path. Can be used in mid-air.
Starts with 2 charges.

Dashes in a line through enemies. Does massive Anemo DMG to enemies you go through/nearby. Causes Swirl reaction if used on element-infused enemies. HAS 2 CHARGES.

Xiao has horrible energy recharge to begin with, as his E generates very few particles. Highly recommended to run another Anemo character (even Anemo MC works) to battery for Xiao. Only ONE charge comes back at the end of the 10s CD.

E does not provide i-frames — you will still get absolutely slapped if you try to dodge with it.

Dissolution Eon: Heaven Fall

Using Lemniscatic Wind Cycling increases the DMG of subsequent uses of Lemniscatic Wind Cycling by 15%. This effect lasts for 7s, and has a maximum of 3 stacks. Gaining a new stack refreshes the effect's duration.

Essentially you can get a 45% DMG buff for E.

PSA #3:

Unfortunately for C0 Xiao, you can’t really maximize the stacks. Most you’ll get is 2 stacks (30% DMG buff), which is still extremely strong – C1 can hit 3 stacks and maintain it easily though.

Q - Bane of All Evil

Xiao dons the Yaksha Mask that set gods and demons trembling millennia ago.

Yaksha's Mask

• Greatly increases Xiao's jumping ability.
• Increases his attack AoE and attack DMG.
• Converts attack DMG into Anemo DMG, which cannot be overridden by any other elemental infusion.

In this state, Xiao will continuously lose HP. The effects of this skill end when Xiao leaves the field.

Xiao puts on his mask and can now jump higher? Changes your normal/charged/plunging attack into Anemo DMG. Your plunging attack will do a large AoE Anemo attack. Oh, it also slowly drains your HP.

IMPORTANT TIP: Unless you have C6, don’t bother using E or normal/charged attacking when Q is up. Just spam that plunging attack as much as you can. You can animation cancel when you land by doing a quick normal attack, AND you can use plunging attack at any point of the jump (a.k.a. don’t wait until you’re at the peak of your jump).

Using E when in Q won’t generate Anemo particles for Xiao, making it even harder to have another Q prepped. This is not an issue if you’re killing enemies (since they drop energy orbs), but can be remedied by simply running another Anemo character to be a battery.

Conqueror of Evil: Tamer of Demons

While under the effects of Bane of All Evil, all DMG dealt by Xiao increases by 5%.
DMG increases by a further 5% for every 3s the ability persists. The maximum DMG Bonus is 25%.

You get a free 25% DMG buff when you Q.

Talent Leveling Order: Normal > Q > E (your E already has crazy multipliers early on)