Star Rail revealing that it is working to improve old characters, a new leak brings more good news about them.

In Honkai: Star Rail, many of the four-star characters might ... revolves around building her Karma stacks (displayed below her portrait on the game’s HUD) by attacking enemies’ weaknesses.

Your second new fighter in Version 3.1 is Mydei, a "warrior as valiant as a lion" who consumes HP to deal extra damage.