Guide
How the kit works
Start Hu Tao's field time with Guide to Afterlife. It consumes a portion of her current HP, pushes nearby enemies back and enters Paramita Papilio. The state raises ATK based on her Max HP when she enters it, up to 400% of her Base ATK. It also converts her attack damage to Pyro and increases her resistance to interruption.
Use Secret Spear of Wangsheng (NA) during that state, especially its Charged Attack. Each Charged Attack that hits applies Blood Blossom, which deals Pyro damage every 4 seconds and counts as Elemental Skill damage. An enemy can have only one Blood Blossom at a time, and only Hu Tao can refresh it. Charged Attacks consume Stamina unless she has her first constellation.
Use Spirit Soother when its area damage or healing is useful. It restores a percentage of Hu Tao's Max HP when it hits, up to five times depending on the number of enemies struck. If her HP is at or below 50% when an enemy is hit, both its damage and healing increase.
Sanguine Rouge also gives Hu Tao 33% Pyro DMG Bonus at or below 50% HP. Paramita Papilio ends when its duration expires, when she leaves the field or when she falls. Once it ends, Flutter By gives the other party members 12% CRIT Rate for 8 seconds.
Build and why
Choose four pieces of Crimson Witch of Flames for a build centered on Pyro and reactions. Two pieces give 15% Pyro DMG Bonus. Four pieces increase Vaporize and Melt damage by 15%, and using an Elemental Skill increases the two-piece bonus for 10 seconds.
Shimenawa's Reminiscence is another option for attacks: its four-piece effect grants 50% Normal, Charged and Plunging Attack damage for 10 seconds after using the skill. It requires at least 15 Energy and consumes that amount. Marechaussee Hunter gives Normal and Charged Attack damage, while changes in current HP can build up its CRIT Rate bonus.
Use HP Percentage or Elemental Mastery on the sands, Pyro DMG Bonus on the goblet, and CRIT Rate or CRIT DMG on the circlet. HP supports the ATK increase from Guide to Afterlife; Elemental Mastery suits a reaction-focused team. For substats, look for CRIT Rate and CRIT DMG first, followed by HP Percentage, Elemental Mastery and Energy Recharge.
Staff of Homa is the first weapon choice. It increases HP by 20% and grants ATK based on Max HP; the ATK bonus increases further when HP is below 50%. Staff of the Scarlet Sands converts Elemental Mastery into bonus ATK and can add more after Elemental Skill hits.
Primordial Jade Winged-Spear gains ATK stacks on hit and grants a damage bonus at maximum stacks. For a four-star option, consider Dragon's Bane: it increases damage against enemies affected by Hydro or Pyro.
Leveling priority
A good leveling order is Secret Spear of Wangsheng (NA) first, Guide to Afterlife second and Spirit Soother third. Her attacks take much of her field time, while the skill supplies the ATK increase and Blood Blossom. The burst still matters for its damage and healing.
For maximum character ascension, you need 420,000 Mora, 168 Silk Flower, 1 Agnidus Agate Sliver, 9 Agnidus Agate Fragment, 9 Agnidus Agate Chunk, 6 Agnidus Agate Gemstone and 46 Juvenile Jade. You also need 18 Whopperflower Nectar, 30 Shimmering Nectar and 36 Energy Nectar.
For all skills to maximum level, the materials are 4,957,500 Mora, 9 Teachings of Diligence, 63 Guide to Diligence, 114 Philosophies of Diligence, 3 Crown of Insight and 18 Shard of a Foul Legacy. Add 18 Whopperflower Nectar, 66 Shimmering Nectar and 93 Energy Nectar.
Constellations worth it
Crimson Bouquet is the standout constellation. During Paramita Papilio, Charged Attacks no longer consume Stamina, making it easier to use them without draining that resource.
Ominous Rainfall is worth considering for Blood Blossom: it adds damage equal to 10% of Hu Tao's Max HP when the effect is applied and lets Spirit Soother apply it. Lingering Carmine adds three levels to Guide to Afterlife.
You can leave the later constellations aside if those effects are not what you need. Garden of Eternal Rest gives nearby allies CRIT Rate after a qualifying Blood Blossom enemy is defeated, while Floral Incense raises the burst level. Butterfly's Embrace prevents a fall under its stated HP or lethal-hit conditions and grants temporary bonuses, but can trigger only once every 60 seconds.
Teams
Hydro teammates give Hu Tao opportunities for Vaporize. Xingqiu and Yelan are Hydro options with an off-field role, so they fit alongside her time on the field. You can use either as a starting point for a team.
Zhongli is a shield option if you want protection while Hu Tao stays at low HP. Citlali offers a Cryo shield option and can fit a Melt team. Kaedehara Kazuha or Sucrose can bring Anemo and Swirl.
Hu Tao mainly gives the team on-field Pyro damage. After her skill state ends, Flutter By gives her teammates CRIT Rate, so they can use that window for their own damage.
Common mistakes
Do not switch Hu Tao out in the middle of Paramita Papilio unless you intend to end it. Her Pyro attack conversion and the rest of the state end when she leaves the field.
Do not ignore Stamina before C1. Charged Attacks consume it, so leave enough for movement when you need to avoid a hit. Low HP grants bonuses, but it also makes taking damage more dangerous.
Watch your Energy with Shimenawa's Reminiscence. Its four-piece effect consumes 15 Energy when its requirement is met, which can leave less available for Spirit Soother. Also remember that its attack bonus does not trigger if you have less than 15 Energy when you use the skill.