Guide
How the kit works
Start by hitting opponents with a teammate's Hydro, Pyro, Cryo or Electro attacks. Foreign Windwrath grants Traveler one Blade of the Dawn Breeze stack for each different type among those hits. At two or more stacks, a Charged Attack consumes them and becomes a special attack. Each hit gains Anemo DMG equal to 60% of Traveler's ATK, and each consumed element creates a matching Blade Wind that deals 50% of ATK as that element.
The special Charged Attack can trigger once every 15 seconds, and Traveler cannot gain stacks during it. Ordinary Foreign Ironwind (NA) attacks have up to five Normal Attack hits. Slitting Wind adds a wind blade to the final hit, dealing Anemo DMG equal to 60% of ATK to opponents in its path.
Use Palm Vortex against opponents in front of you. It deals continuous Anemo DMG and ends in a larger explosion. Holding it gradually increases its damage and area. Contact with Hydro, Pyro, Cryo or Electro lets it absorb one element per use and deal extra damage of that type.
Gust Surge sends a tornado forward, pulling objects and opponents while dealing continuous Anemo DMG. It can also absorb one eligible element per use. Second Wind restores 2% HP for 5 seconds after a Palm Vortex kill; it can trigger once every 5 seconds.
Build and why
Use four pieces of Viridescent Venerer for a Swirl support build. Two pieces give 15% Anemo DMG Bonus; four increase Swirl DMG by 60% and lower the opponent's RES to the element infused in Swirl by 40% for 10 seconds. Trigger Swirl with the element your team wants to deal damage with. RES reductions of the same elemental type from this set do not stack.
Noblesse Oblige is another team option: its four-piece effect gives the party 20% ATK for 12 seconds after Traveler uses a burst. Instructor is an alternative for reaction teams, giving the party 120 Elemental Mastery for 8 seconds after Traveler triggers an Elemental Reaction. Two pieces of Viridescent Venerer plus two of Wanderer's Troupe are also worth considering for Anemo DMG Bonus and 80 Elemental Mastery.
Choose Elemental Mastery on the goblet and circlet, with Elemental Mastery or Energy Recharge on the sands. For substats, look for Elemental Mastery first, then Energy Recharge, ATK Percentage, CRIT Rate and CRIT DMG. Energy Recharge helps when you want the burst available more often.
Freedom-Sworn is the first weapon choice: it increases DMG by 10% and gains Sigils of Rebellion when its wielder triggers Elemental Reactions. Primordial Jade Cutter is another damage option, adding HP and an ATK Bonus based on Max HP. Iron Sting increases all DMG after Elemental DMG, with up to two stacks. Xiphos' Moonlight is worth considering for its Energy Recharge effect based on Elemental Mastery.
Leveling priority
A sensible leveling order is Palm Vortex first, Gust Surge second and Foreign Ironwind (NA) last. The skill and burst both deal Anemo DMG over an area and can absorb another element. Raise the Normal Attack earlier if you spend more time attacking with Traveler on the field.
For maximum ascension, the materials are 420,000 Mora, 168 Windwheel Aster, 1 Brilliant Diamond Sliver, 9 Brilliant Diamond Fragment, 9 Brilliant Diamond Chunk, 6 Brilliant Diamond Gemstone, 18 Damaged Mask, 30 Stained Mask and 36 Ominous Mask.
For all talents to maximum, you need 4,957,500 Mora, 9 Teachings of Freedom, 18 Guide to Freedom, 18 Philosophies of Freedom, 33 Guide to Resistance, 36 Philosophies of Resistance, 12 Guide to Ballad, 60 Philosophies of Ballad, 3 Crown of Insight, 18 Divining Scroll, 66 Sealed Scroll, 93 Forbidden Curse Scroll and 18 Dvalin's Sigh.
Constellations worth it
Intertwined Winds is the standout constellation. Enemies damaged by Gust Surge lose 20% Anemo RES. If the tornado absorbed an element, those enemies also lose 20% RES to that element. Aim the tornado where it can hit the enemies your team is attacking.
Raging Vortex is useful to consider next: Palm Vortex pulls opponents and objects within 5 meters. Uprising Whirlwind gives 16% Energy Recharge, which helps with burst availability.
Sweeping Gust adds three levels to the burst, while Vortex Stellaris adds three to the skill. Cherishing Breezes reduces damage taken while casting the skill by 10%. You can leave those upgrades for later if you are focused on grouping and team support; they do not provide the resistance reduction of C6.
Teams
Bring teammates who can hit enemies with Hydro, Pyro, Cryo or Electro. Those elements give Traveler targets for Swirl and can be absorbed by the skill or burst. Two different eligible elements also let teammate hits build the stacks needed for the special Charged Attack.
Common mistakes
Do not assume every enemy will stay close to you after Gust Surge. The tornado moves forward, so consider its direction before casting. With C6, enemies have to take its damage to receive the RES reduction.
Do not confuse absorption with a free choice of element after casting: Palm Vortex and the tornado each need contact with an eligible element, and each can absorb only once per use. Apply the element you want before using them.
Avoid relying on the four-piece Wanderer's Troupe Charged Attack bonus for Traveler. That bonus applies to Catalyst and Bow users, not Sword users. Also, do not expect Second Wind to replace a team healer: it requires a Palm Vortex kill and restores Traveler's own HP.