Building Shenhe in Genshin Impact is the first step to using her in the party. It appears that miHoYo intends to keep releasing element-specific supports in the game. Previously, there's Kujou Sara that's designed for Electro DPS, then Gorou in Genshin Impact is best used for defensive Geo units. As for Shenhe, of course, she will be a Cryo support.