A Genshin Impact leak reveals a screenshot featuring a new elemental reaction which is tied with the new Dendro element which is expected to arrive with Sumeru.
There is a total of seven different elements in Genshin Impact, all of which are attached to the game's character, except one. We are yet to see a playable Dendro element user in the world of Teyvat.
A recent tweet by a credible Genshin Impact leaker reveals more information about two new Elemental Reactions - Overgrown and Intensified. So far there is no confirmation which elements will trigger those reactions but most players predict that both will include the Dendro element.
The same leaker has now confirmed that the new reaction Intensified (also known as Overdose) will have a great Elemental Mastery scaling. However, it will probably work independently from all the other reactions, similar to Geo's Crystalize. A new Genshin Impact leak reveals a screenshot featuring a new Elemental Reaction that is tied with Dendro.
So far the only elemental reaction that includes Dendro is Burning. The grass is considered a Dendro object and will spread the burn effect around the area. The fact that this element only interacts with Pyro might be one of the reasons why we haven't seen a Dendro character yet. It would surely require a major change to the elemental reaction fighting mechanics of the game.
Dendro is heavily tied with the region of Chasm which is already present on the current in-game map, southwest of Liyue. Chasm will most likely bring two new characters Yaoyao and Baizhu. Back in November 2020, a credible leaker by the name Zeniet has tweeted a picture featuring eight character models. So far seven of these characters have been introduced to the game with Yaoyao being the only exception.