Anemo characters are the only characters in-game that can take maximum benefit from Viridescent Venerer artifacts because of their ability to trigger swirl reactions. This artifact set can be used on almost every anemo character, except for Xiao. Because Xiao's kit is more damage-oriented, it's better to use other artifact set bonuses on him. This doesn't mean he cannot use Viridescent Venerer; he can. However, that's not an optimal choice. Coming to the question, you should use anemo characters where you can take the most benefit from elemental reactions of elemental damage. They can help your character reach insane damage when triggering transformative or amplifying reactions.