PSA #1:

If you have legal problems, you go get a good lawyer. Same with your DPS: you want something dead, you go get a good DPS.

PSA #2:

Both Yanfei’s abilities scale off ATK, and basically she’s like a bootleg, older version of Klee. Except instead of a bomb, she drops a giant stamp on you.

E = Elemental Skill = Signed Edict

Q = Elemental Burst = Done Deal

Auto Attack - Seal of Approval

Normal Attack
Shoots fireballs hat deal up to three counts of Pyro DMG.
When Yanfei's Normal Attacks hit enemies, they will grant her a single Scarlet Seal. Yanfei may possess a maximum of 3 Scarlet Seals, and each time this effect is triggered, the duration of currently-possessed Scarlet Seals will refresh.
Each Scarlet Seal will decrease Yanfei's Stamina consumption and will disappear when she leaves the field.

Charged Attack
Consumes Stamina and all Scarlet Seals before dealing AoE Pyro DMG to opponents after a short casting time.
This Charged Attack's AoE and DMG will increase according to the amount of Scarlet Seals consumed.

Plunging Attack
Gathering the power of Pyro, Yanfei plunges towards the ground from mid-air, damaging all opponents in her path. Deals AoE Pyro DMG upon impact with the ground.

This is her bread and butter. Normal Attacks give her a seal, stacking up to 3 times. More charges she gains, less stamina she uses for Charged Attacks and they do more damage. Each seal lasts 10s independently.

Proviso

When Yanfei consumes a Scarlet Seal by using a Charged Attack, each Scarlet Seal will increase Yanfei's Pyro DMG Bonus by 5% for 6s. When this effect is triggered again while its current duration lasts, it will dispel the previous effect.

Basically you can get a 5/10/15% increase to Yanfei’s Pyro DMG bonus.

IMPORTANT TIP: IT OVERRIDES THE LAST BUFF. So if you were to first stack 3 seals then Charged Attack, then your Pyro DMG% will gain receive 15% Pyro DMG Bonus. However, if you then stack 2 seals and Charged Attack, it will remove the 15% bonus you received and grant 10%.

So if you had 12% Pyro DMG Bonus, consuming 3 stacks would raise it to 27% Pyro DMG Bonus. If you then consume 2 stacks, then it’ll go down to 22% Pyro DMG Bonus.

You’ll know how many stacks were consumed, as it shows a giant white number on Yanfei when you do.

Blazing Eye

When Yanfei's Charged Attacks deal CRIT Hits, she will deal an additional instance of AoE Pyro DMG equal to 80% of her ATK. This DMG counts as Charged Attack DMG.

If Charged Attack CRIT’s, then does a second pulse of AoE Pyro DMG. This can be affected by Charged Attack DMG bonuses like 4-set Wanderer’s, her Q’s bonus, etc… It’s what makes her Charged Attack so good.

The only gripe with this (not really a big issue though) is that the second pulse sometimes makes it tricky to properly proc a melt reaction to maximize the damage, as it will apply Pyro. Not too significant, but can be annoying for those who like to min-max.

E - Signed Edict

Summons blistering flames that deal AoE Pyro DMG.
Opponents hit by the flames will grant Yanfei the maximum number of Scarlet Seals.

Yanfei just blows up the area infront of her, doing AoE Pyro DMG. This grants you max seal stacks.

IMPORTANT TIP: Start with E into Charged Attack for every fight! That way you can maximize your initial burst going into a fight, or even a rotation. If you have C6, then it’ll grant 4 seals.

Done Deal

Triggers a spray of intense flames that rush at nearby opponents, dealing AoE Pyro DMG, granting Yanfei the maximum number of Scarlet Seals and applying Brilliance to her.

Brilliance
Has the following effects:

• Grants Yanfei a Scarlet Seal at fixed intervals.
• Increases the DMG dealt by her Charged Attacks.

The effects of Brilliance will end if Yanfei leaves the field or falls in battle.

She seals the deal by dropping a giant stamp on her enemies doing massive AoE Pyro DMG, and granting a Charged Attack buff + generates seals.

To better explain: During the 15s duration, Yanfei will have the “Brilliance” buff which gives her a Charged Attack buff and generates a seal every second. You can roughly get 4 fully stacked Charged Attacks during this buff, so maximize it during opportune burst windows etc…

PSA #3:

Don’t waste time stacking 3 seals — 2 Normal Attacks into Charged Attack is better.

Her third Normal Attack has a slower animation, so it’s much faster to spam 2-1 which leads to more DPS overall. Obviously you can use 1-1 if you want to chain reactions faster.

Example: At 2 stacks, you’ll get 30% (15% per stack) reduced Charged Attack stamina consumption and her Charged Attack damage will be 133% of her ATK.

THE SEALS DISAPPEAR IF YOU SWAP OUT.

Talent Leveling Order: Normal > Q > E (reason why Q > E is because leveling Q also enhances Charged Attack bonus it grants)