Spoiler..
yes. but after his father consumed the energy in it. He notice there’s still faint energy in there. it’s like a egg of groot wood or whatever the tree monster called. he tried to make a bond on it too but he can’t since he’s not a wood bender or something i don’t really understand. that’s why he gave it to the elf girl . since he think she will be compatible with it since the egg and the girl have the same affinity or so they say. That’s why they all get shock (the principal of the academy and the elf grandpa) when they know what kind of gift he gave to her. i stop reading after he gave it to her. i don’t know what happened afterwards.
So the guradian core being left behind, does anyone know if its gonna play a role later on, just cuz thats kinda sus