BlishHUD is a 3rd party addon for GW2 that displays additional game information. It is quite popular but unfortunately it also was really hard to get running on Linux because on Windows it runs as a transparent window on top of the game. There are solutions for kwin that workaround that by using a shader but that lead to ugly artifacts around the BlishHUD windows. I recently found a project called external-dx11-overlay while searching for a better solution. It runs BlishHUD with a dx11 render hook inside of the game and from my testing so far it seems flawless.