How Old is Diluc Genshin Impact
According to Genshin Impact, Diluc is about 22 years old. The evidence is that his 18th birthday was when his father died, and he started a crusade against the Fatui. He traveled all over Teyvat for four years, then returned to Mondstadt.
That seems reasonable until you consider the manga. It states that Diluc returned after three years and that the events in it happened about a year before the beginning of the game. Fortunately, this doesn’t change his age, as it only affected the timing of when he returned to Mond.