okay so major spoilers in response to this so don't read it if you're not ready.
Um yes he damaged his core bc long story short a person who knew him in his last life is mad at him. You know the type of magic he uses with Slyvia's core,, it's called aether and bc Arthur almost died in that battle i just mentioned she saves him which turns Arthur into like a part dragon thing. He's now able to use aether and makes a new core with it making him 10x stronger but now he has to start all over (but he can now do things like teleport and see the future idk it didn't make sense). SYLVIE IS NOT DEAD just like put on pause bc she like kinda sacrificed herself for Arthur.
Periodt and SPOILER
Can someone tell me if he gets stronger after he broke his cure??? I heard it got broken and he got weakened does he get even stronger even before???? I also heard slilvy died is it true and tev got raped??? Pls anyone help!!! Spoill mee pls