ROM Hack Question Need help with Jotun Valhalla Edition save hacking

[kamo]

I've tried to edit some variables with the help of https://www.saveeditonline.com/ but while I could change some stuff it never showed up ingame. I think I need to decrypt that file first but I don't know how. Any help please?
I attached the save. The forum software didn't like that it hadn't any file extension so I've added '*.txt'