Iansan functions as a specialized Electro support character in Genshin Impact, specifically designed to empower high-mobility damage dealers through an innovative movement-based buffing system. Unlike traditional stationary buffers, Iansan provides a dynamic Attack (ATK) bonus that rewards active characters for repositioning during combat. This mechanic, centered around her Kinetic Energy Scale, positions her as a cornerstone for many Natlan-based team compositions that utilize the Night Soul system.

Core Mechanics and Talent Priority

Iansan's utility is almost entirely concentrated in her Elemental Burst, "The Three Principles of Power." Upon activation, she deploys the Kinetic Energy Scale, a following entity that boosts the active character's ATK based on Iansan's current Night Soul points and her total ATK stat.

A critical threshold for Iansan is reaching 42 Night Soul points. When her points are below this value, the buff scales dynamically with her remaining points. However, once she hits 42 points, the scale enters the "Ardent Support!" state. In this mode, the ATK bonus ignores her remaining Night Soul points and instead provides a significantly higher flat buff based solely on her total ATK. This makes managing her Night Soul point generation through character movement and her Elemental Skill, "Thunderbolt Rush," the primary focus of her gameplay loop.

Her Elemental Skill provides the necessary mobility to navigate the battlefield while simultaneously regenerating Night Soul points. When used within Natlan, it also integrates with the Phlogiston system, allowing for enhanced exploration and combat repositioning.

Talent Leveling Priority:

  1. Elemental Burst (The Three Principles of Power): This is the highest priority as the ATK buff percentage scales directly with talent levels.
  2. Elemental Skill (Thunderbolt Rush): Secondary priority for personal damage and Night Soul point management.
  3. Normal Attack (Weighted Spike): Generally safe to leave at level 1, as Iansan spends minimal time on-field performing basic attacks.

Best Artifact Sets for Iansan

The optimal artifact selection for Iansan is heavily influenced by her role as a Natlan support. Her kit is designed to trigger and benefit from Night Soul Burst mechanics, making certain sets vastly superior to generalist options.

1. Scroll of the Hero of Cinder City (4-Piece)

This is the definitive best-in-slot set for Iansan. The 2-piece effect provides energy regeneration whenever a nearby party member triggers a Night Soul Burst, which is vital for Iansan's high 80-energy cost Burst. The 4-piece effect is transformative: triggering an elemental reaction grants all party members a 12% Elemental DMG bonus. Furthermore, if the wearer is in the Nightsoul's Blessing state (which Iansan enters via her Skill and Burst), this bonus increases by an additional 28%. Totaling a 40% DMG bonus, this set allows Iansan to provide both massive ATK buffs and significant elemental scaling.

2. Noblesse Oblige (4-Piece)

For players who have not yet optimized a Cinder City set, Noblesse Oblige remains a viable alternative. It provides a standard 20% ATK buff to the entire team upon using a Burst. While consistent, it lacks the Elemental DMG amplification of the Natlan-specific set and does not assist with Iansan's personal energy requirements as effectively.

3. Songs of Days Past (4-Piece)

In teams where Iansan's minor healing (from her second passive talent, "Kinetic Energy Gradient Test") is utilized to supplement party survival, this set can provide a small additional flat damage bonus. However, it is generally considered a niche option compared to the offensive power of Cinder City.

Artifact Main Stats and Substat Targets

Building Iansan requires a balance between meeting her demanding Energy Recharge (ER) thresholds and maximizing her total ATK to boost the potency of her buffs.

  • Sands: Energy Recharge % or ATK %
  • Goblet: ATK %
  • Circlet: ATK % (or Crit Rate if using Favonius Lance)

Substat Priority: Energy Recharge > ATK % > Flat ATK > Elemental Mastery.

Energy Recharge Thresholds

Iansan’s Burst cost is 80, making ER the most important stat until her rotation is seamless.

  • Solo Electro: 220% – 250% ER.
  • With a second Electro character (e.g., Clorinde, Raiden): 160% – 180% ER.
  • With Favonius weapons on the team: Reduce requirements by approximately 15-20%.

ATK Benchmarks

To provide a competitive buff that rivals other top-tier supports, Iansan should aim for a minimum of 2,500 total ATK. High-investment builds utilizing 5-star weapons can easily reach 3,000+ ATK, further scaling the impact of her Kinetic Energy Scale.

Top Weapon Choices

Iansan benefits from polearms that provide high base ATK or significant Energy Recharge substats. Since her buff scales off her total ATK (not just base ATK), weapons with ATK % passives are highly valuable.

5-Star Options

  1. Symphoniest of Scents: Often considered her premium option, this weapon provides a massive ATK boost when the character is off-field. It also triggers an additional team-wide ATK buff when the wielder initiates healing, which perfectly aligns with Iansan's passive healing talent.
  2. Calamity Queller: With the highest base ATK in the game (741 at level 90) and an off-field ATK stacking passive, this weapon maximizes the raw numbers of Iansan's Burst buff. It does, however, necessitate very high ER substats on artifacts.
  3. Engulfing Lightning: An excellent choice for balancing her needs. It converts Energy Recharge into ATK %, allowing Iansan to stack ER for consistency while still gaining offensive scaling for her team buffs.

4-Star and F2P Options

  1. Favonius Lance: The gold standard for utility. It solves Iansan's energy issues and provides white particles for the entire team. This is often the most comfortable weapon for general play, though it requires a Crit Rate circlet to trigger the passive reliably.
  2. Tamayura Tei no Ohanashi (Event Weapon): A strong free-to-play choice that offers ER and an ATK bonus after using an Elemental Skill. It is specifically tailored for Natlan supports who need to balance these two stats.
  3. Wavebreaker’s Fin: Provides high base ATK for a 4-star and increases Burst DMG. While the Burst DMG is less relevant for a support build, the high base ATK contributes well to her buff scaling.

Best Team Compositions for Iansan

Iansan's unique requirement—active character movement to regenerate her Night Soul points—makes her incompatible with stationary "circle impact" DPS units. She thrives in teams where the main damage dealer is constantly dashing, jumping, or repositioning.

1. The Natlan Hyper-Mobile Team

  • Main DPS: Kinich / Mualani
  • Sub-DPS: Mavuika (Pyro Archon)
  • Support: Iansan
  • Flex/Healer: Bennett or Xilonen

In this composition, Kinich or Mualani utilize their high-speed movement skills to constantly feed distance data to Iansan’s Kinetic Energy Scale. This ensures the buff remains in the "Ardent Support!" state for the duration of their field time. Mavuika provides consistent Pyro application and additional offensive pressure, while Iansan amplifies the entire team's ATK and provides Electro-related reactions (Overload or Vaporize/Electro-Charged depending on the fourth slot).

2. Electro-Charged / Overload Carry

  • Main DPS: Clorinde
  • Sub-DPS: Furina
  • Support: Iansan
  • Utility: Citlali or Xianyun

Clorinde’s rapid lunges during her Elemental Skill window are perfect for maintaining Iansan’s buffs. When paired with Furina, Iansan’s passive healing helps counteract Furina's HP drain, while Iansan provides the necessary ATK steroids that Clorinde craves. The addition of Citlali or Xianyun adds further layers of reaction damage or mobility-based buffs.

3. F2P Friendly Overload

  • Main DPS: Sethos or Gaming
  • Support: Iansan
  • Sub-DPS: Xiangling
  • Utility: Chevreuse

This team leverages the Overload reaction. While Gaming is Pyro, his plunging attacks involve significant vertical and horizontal movement, which registers for Iansan's scale. Chevreuse provides Pyro and Electro resistance shred, making Iansan’s personal Electro application more impactful while Iansan boosts the ATK of the Pyro carries.

Constellation Analysis

As a 4-star character, Iansan’s constellations significantly improve her ease of use and the ceiling of her support capabilities.

  • C1 (Starting's Never Easy): Provides energy restoration based on Night Soul points consumed. This is a vital quality-of-life upgrade that lowers her ER requirements.
  • C2 (Laziness is the Enemy!): Automatically grants the "Precise Movement" effect (ATK +20%) upon using her Burst. This simplifies her rotation by removing the need to hit an enemy with her skill first to maximize her own ATK before buffing the team.
  • C4 (Efficiency Above All): Reduces the cooldown of her Elemental Burst when certain movement conditions are met, allowing for nearly 100% uptime on her Kinetic Energy Scale.
  • C6 (The Ultimate Trainer): This constellation provides a massive boost to the active character’s Crit DMG if they are within the "Ardent Support!" state of her Burst. This elevates Iansan from a standard ATK buffer to a top-tier offensive support comparable to C6 4-star specialists like Faruzan or Sara.

Advanced Playstyle Tips and Rotations

To maximize Iansan's potential, the player must understand the rhythm of her Night Soul generation. The Kinetic Energy Scale logs movement every second. If the active character stops moving, the restoration of Night Soul points drops significantly, potentially causing the scale to exit the "Ardent Support!" state.

Standard Rotation:

  1. Start with your setup supports (e.g., Furina Burst or Mavuika Skill).
  2. Switch to Iansan and use her Elemental Skill to enter Nightsoul's Blessing and gain initial points.
  3. Immediately trigger Iansan's Elemental Burst. This snapshots her current ATK (make sure any external buffs like Noblesse or weapon passives are active) and deploys the scale.
  4. Switch to your Main DPS and begin your offensive string, ensuring you are using dashes or movement-based skills to keep the scale's points high.
  5. If using a character like Kinich, use his grappling hook frequently to maintain maximum distance traveled.

Ascension and Talent Materials

For players preparing to maximize Iansan, the following materials are required for her full ascension and talent progression (Level 90, 1/10/10):

Ascension Materials:

  • Vajrada Amethyst Gems: Standard Electro stones dropped by Electro bosses.
  • Ensnaring Gaze: Boss drop from the Natlan-based automaton or elite beast enemies.
  • Dracolite: Regional specialty found primarily in the mountainous regions of Natlan.
  • Whistle Series (Sentry/Warrior/Saurian-Crowned): Common drops from tribal warriors in Natlan.

Talent Materials:

  • Contention Series (Teachings/Guide/Philosophy): Weekly talent books available in the Natlan domains.
  • Denial and Judgment: Weekly boss drop from the 6.x series trounce domain.
  • Crown of Insight: For the final level of her Elemental Burst.

Conclusion: Is Iansan Worth Building?

Iansan represents a shift in Genshin Impact's support philosophy, moving away from static circles and toward active engagement with the game's movement mechanics. While her healing is not sufficient to be a solo sustain in high-difficulty content like the Spiral Abyss without careful play, her offensive contributions are immense.

For players who primarily use Natlan characters or high-mobility units like Clorinde and Kinich, Iansan is a transformative addition. Her ability to provide massive ATK buffs and 40% Elemental DMG bonuses (via the Cinder City set) makes her one of the most versatile 4-star supports released in the 6.0 era. Even at lower constellations, her impact is felt, but at C6, she becomes a mainstay for any ATK-scaling Electro or Overload team. Focusing on a high-ATK, high-ER build will ensure she remains a reliable pillar of your roster through the Natlan cycle and beyond.