Xingqiu is a Hydro element support type character. His elemental skill can act as a shield for your character since it reduces damage taken and increases your resistance to interruption, as well as some small heal if you ascend him once. His elemental burst will also create some rain swords, but unlike the elemental skill, the rain swords will not shatter when you take damage and will last until the duration is over. Additionally, water swords will rain whenever you do a normal attack. This can be really good if paired with another party member that can take advantage of elemental reaction like Lisa, or Diluc for more damage.