Reactions
When Anemo meets certain other elements, it can trigger Swirl. Swirl can deal elemental DMG, affect beings, and generate further Elemental Reactions.
An upgraded form of (Cryo) Swirl introduced in Snezhnaya: when Anemo reacts with Cryo while a party member able to trigger Stellar reactions is present (as of Version 7.0: Sandrone, the Cryo Traveler, or Odette), the reaction becomes Stellar Swirl instead of ordinary Swirl. It deals a small amount of Anemo DMG in a small AoE and spawns or strengthens a Stellar Vortex; repeated triggers raise the Vortex's level, and it detonates for damage after 4.5s (or immediately once fed by 6 Swirls). Vortex damage scales on Elemental Mastery and CRIT, weighted toward whichever contributing character has the highest EM/CRIT/Stellar DMG stats. Triggering Stellar Swirl (or Stellar-Conduct) counts as triggering the umbrella Stellar Glimmer reaction.