When the patrons of Mondstadt's taverns are asked about the strongest knight of the Knights of Favonius, three names are likely to come up:

The highly reputable Acting Grand Master Jean, Cavalry Captain Kaeya, and the mysterious tycoon, Diluc.

However, some claim to have witnessed, albeit through bleary, drunken eyes, a knight in red, leveling the entire Stormbearer Mountains.

If one wants to find this mysterious knight, then they need look no further than the solitary confinement cell.