Avada Kedavra - is there any way to relearn the spell?

[strong pewter]

hi all,

first time player in hogwarts and just completed all of the main quests. i didn't realize that if i selected "we must turn sebastian in", it would prevent me from learning the curse... so..! is there any way to relearn the curse after selecting that option or do i have to make a new character....start from scratch...and progress my way up again?

feeling kind of frustrated because i honestly didn't know that selecting those options would prevent me from learning the spell. :o)
thank you for the help.

[ivory delta]

I'm not at this part but i know that with this option, sebastian goes to azkaban, so he'll not be in the crypt to learn all the unforgivable curses afterwards :/ So yeah basically you had to create a new character