There’s been a few posts on this, but not all the information is in one place, and people seem very confused about these effects, so I thought I’d put it all in one place with examples.
What is Swirl?
Swirl is an Elemental Reaction cause by certain Anemo (wind) skills. It causes one elemental effect (pyro, hydro, electro, or cryo) to spread to other enemies in the area. In order to trigger Swirl, it has to be applied after the first element. If you use an anemo skill on a hilichurl and then a pyro skill, you will not get a swirl.
If you use a pyro skill and then a hydro skill, and then an anemo skill, you will also not get a swirl. Pyro and hydro will react and cause vaporize, which uses up the hydro and pyro effects.
If you use a pyro skill, then an anemo skill, then a hydro skill, you will swirl and spread the pyro effect. You will only get melt on enemies you hit with the hydro skill. Swirl is a one-time thing, it won’t continue.
ahh that is because of something else. Allow me to introduce you to ELEMENTAL ABSORPTION. This is an extra effect that some skills have. If you use Venti’s Q skill (that’s his ultimate, for you mobile/ps4 users out there), and then throw a pyro attack at the skill – Venti’s Q will absorb the pyro element. It is now a pyro/anemo skill. Every hit it does from now on does both pyro and anemo damage. If you hit a hilichurl in the AoE with hydro, it will react with both pyro and anemo on that hilichurl, and cause vaporise to the hilichurl, then swirl the hydro to everything else, then cause vaporise on everything else.
This chain effect is specific to skills with Elemental Absorption. You can see whether a skill has this if you look at its info. Also, this effect only applies to that specific casting. It doesn’t carry over onto future casts.
The traveller’s Q AND E have elemental absorption, however the E only has elemental absorption when you hold it. Venti and Sucrose’s Q skills have Elemental Absorption, but their E skills do not. Neither of Jean’s skills have elemental absorption.
Ok but when is this important?
This is important in every situation, but in different ways. First, lets examine situations where you are *not* using an elemental absorption skill.
Lets look at Melt, Vapourize, and Freeze. These effects are single target. There is no AoE element. Say you’re using Kaeya, Xiangling, and Sucrose and you want to melt all the things, but you don’t have Sucrose’s Q charged. You’re up against a bunch of hilichurls. You can only spread one elemental effect using swirl. Therefore, you want to use Kaeya’s E to apply cryo to a few things, spread it to anything you missed with Sucrose’s E, and then use any of Xiangling’s skills to apply pyro. This will trigger melt once, and only once, on anything that Xiangling hits with a pyro skill.
Now, lets look at the AoE elemental effects: Superconduct and Overload. Superconduct does AoE cryo damage, overload does AoE pyro damage. If you want to trigger superconduct on everything in an AoE, you should apply the electro status first. Then swirl. Then apply cryo. This will trigger a superconduct explosion on anything you hit, which will then do AoE cryo damage, triggering superconduct on anything nearby that still has the electro status.
If you want to trigger overload on a bunch of stuff using swirl, you must, again, swirl electro on everything, then hit with pyro, causing a chain reaction.
Finally, Electro-charged. This is a little different, because it’s not quite AoE, and it doesn’t quite chain react in the same way. However, order is still important. When you apply electro charged to an enemy, it deals damage twice. The first time is single target. The second hit will also hit one nearby enemy that is wet. This second hit does *not* trigger another electro-charged effect, and it will *not* consume wet.
What do we need to consider if we are using an Elemental absorption skill?
Order still matters, but it’s a little easier. Firstly, all the Elemental absorption skills are damage over time. Or, to be more specific, they hit multiple times each time you cast them. This means that you can cast the Anemo skill first if you like, and then apply the element you want it to absorb. Or the other way around, both will work. Like I said before, when a skill absorbs an element, it becomes double-element. If you cast the traveller’s Q skill and pull an electro slime into it or shoot one of Fischl’s charged electro shots into it, that skill will now do electro and anemo damage with each hit, using the traveller’s stats. When you’re thinking of your combos, this is important when the order of elements matters.
When does order matter? In theory, only with Melt and Vapourise.
Melt: If you trigger melt with cryo first then pyro, you get 2x damage. If you do it the other way around, you get 1.5x damage.
Vapourise: If you trigger it with Pyro first then Hydro, you get 2x damage. The other way around, 1.5.
But what about Elemental Mastery and other stats?
Aha. This is where order matters more often.
An elemental reaction uses the stats of the character who triggered it.
If a hilichurl is burning, and Traveller uses Swirl to apply Hydro to it, then your Traveller caused the reaction. It doesn’t matter where the hydro came from.
If you cast Traveller’s Q and it absorbs Hydro, and a burning hilichurl gets pulled into it, then Traveller triggers the reaction.
If you have a bunch of Hilichurls in Traveller’s Q, and it absorbs Hydro, but then you switch to Xiangling and summon Guoba, then Xiangling triggers the reaction. This applies even if you switch back to the Traveller before Guoba spews fire. Keep this in mind when you’re setting up your teams.
The only special case currently is Chongyun’s E skill. This skill does damage, but it also creates an area which imbues normal attacks with Cryo. If Xiangling is in this area when she attacks, and her attacks trigger a reaction with cryo, then Xiangling triggered it, not chongyun.
That’s a lot of words, but I hope that clarifies things for anyone still confused!