you probably need to open your character save file and find the section of perks, then delete IMPOTENCE from it
In the game itself or the files? I've looked, but I can't see it anywhere
your character file. you can go to the folder that has save files on PC by pressing a button on Load screen. or you can export the save itself on Android. it's called save1.json or similar. Edit it like txt files, find perks section