Guide
How the kit works
Set up your teammates first. Secret Rite: Chasmic Soulfarer normally sends Cyno forward with an Electro thrust. The passive A Star With Which to Start the Journey also puts him in Pactsworn Pathclearer for 6 seconds when he uses the skill outside that state.
Use Sacred Rite: Wolf's Swiftness to enter its Pactsworn Pathclearer state. Normal, Charged and Plunging Attacks become Electro damage that cannot be overridden. Cyno also gains Elemental Mastery, interruption resistance and immunity to Electro-Charged damage.
Attack during the Burst state and use Secret Rite: Chasmic Soulfarer again. It becomes Mortuary Rite, dealing AoE Electro damage and extending the state, up to its 18-second maximum.
Featherfall Judgment puts Cyno in the Endseer stance at intervals during the Burst state. Using the skill then triggers Judication: the skill deals 35% more damage and fires three Duststalker Bolts, each dealing 100% of Cyno's ATK as Electro damage. The bolts count as Elemental Skill damage.
Authority Over the Nine Bows adds damage based on Elemental Mastery: 150% of its value to Pactsworn Pathclearer Normal Attacks and 250% to Duststalker Bolts. Outside the state, Invoker's Spear (NA) gives Cyno up to four consecutive spear strikes.
Build and why
Use four pieces of Thundering Fury as the first set to consider. Its two-piece bonus gives 15% Electro DMG Bonus. The four-piece bonus strengthens several reactions, including Aggravate and Hyperbloom, and triggering the listed reactions or Quicken can reduce Elemental Skill cooldown by 1 second.
Four pieces of Gilded Dreams are another option. The two-piece bonus gives 80 Elemental Mastery; after a reaction, the four-piece bonus gives ATK for teammates with Cyno's element and Elemental Mastery for teammates with different elements. Gladiator's Finale is a simpler alternative: its four-piece bonus increases a Polearm user's Normal Attack damage by 35%.
For the sands, choose Elemental Mastery, ATK Percentage or Energy Recharge. Use Electro DMG Bonus or Elemental Mastery on the goblet, and CRIT Rate or CRIT DMG on the circlet. Look for CRIT Rate and CRIT DMG in substats, followed by Elemental Mastery, Energy Recharge and ATK Percentage.
Staff of the Scarlet Sands is the first weapon choice. It converts 52% of Elemental Mastery into bonus ATK, with further stacks when the skill hits. Primordial Jade Winged-Spear builds ATK stacks on hits and adds damage at maximum stacks. Ballad of the Fjords gives 120 Elemental Mastery when the party has at least three different elements.
Staff of Homa is another option, with an ATK bonus based on Max HP. For a simpler Normal Attack weapon, White Tassel increases their damage by 24%.
Leveling priority
A suggested order is Sacred Rite: Wolf's Swiftness, then Secret Rite: Chasmic Soulfarer, then Invoker's Spear (NA). The Burst sets up Cyno's main on-field state, while the skill is used repeatedly during it. Level the basic attack last if most of your fighting happens in that state.
For full ascension, gather 420,000 Mora, Scarab, the Vajrada Amethyst materials, Divining Scroll, Sealed Scroll, Forbidden Curse Scroll and Thunderclap Fruitcore.
To raise all talents to their maximum, you also need 4,957,500 Mora, Crown of Insight, Teachings of Admonition, Guide to Admonition, Philosophies of Admonition, the three scroll materials and Mudra of the Malefic General.
Constellations worth it
Ordinance: Unceasing Vigil is the first upgrade to look at. After the Burst, it gives 20% Normal Attack Speed for 10 seconds. Triggering Judication refreshes that duration, so it rewards the skill timing you already want to use.
Raiment: Just Scales adds Duststalker Bolts to Normal Attack hits. The Burst or a Judication trigger grants four stacks, and each qualifying hit consumes one. The effect has a maximum of eight stacks, and it can fire a bolt this way at most once every 0.4 seconds.
Ceremony: Homecoming of Spirits gives 10% Electro DMG Bonus when a Normal Attack hits, up to five stacks. Each stack lasts 4 seconds, so keep attacking to maintain the bonus.
Austerity: Forbidding Guard is worth considering for team Energy: qualifying reactions during the Burst state restore 3 Energy to each nearby teammate, but not Cyno, up to five times per Burst. The third and fifth upgrades add levels to the Burst and skill respectively; you can stop before them if you only want the earlier effects.
Teams
Cyno gives the team sustained Electro attacks and reaction opportunities during his field time. At his fourth constellation, qualifying reactions can also restore Energy to his teammates.
Common mistakes
Do not switch Cyno out in the middle of his Burst state unless you are ready to end it. Prepare your team's abilities beforehand and give him enough room to attack.
Do not use every skill activation without watching for Endseer. Activating Secret Rite: Chasmic Soulfarer during that stance gives the extra Judication damage and bolts. Its cooldown can also change when Thundering Fury triggers.
Do not ignore Elemental Mastery when choosing artifacts. Authority Over the Nine Bows uses it to increase Normal Attack and Duststalker Bolt damage. At the same time, Energy Recharge is an option on the sands if you need more Energy for the Burst.
Do not assume Cyno's interruption resistance or immunity to Electro-Charged damage protects him from all damage. Bring healing or a shield when the fight calls for it.