I bound St Ydems Redeemer to Eder and was at 450+/500 damage done to spirits and now it's unbound and if I bind it again, the progress is back at 0.
I will try to upload a save if a have the courage to launch the game again (but I have already lost several hours with the different bugs plaguing the game like the items disappearing - doing the same content and fights several time isn't my definition of fun).