u/Ghosty_Fellow

Okay so i cant remember its name but i remember the gist pretty much when the kids of this world were a certain age theyd be taken to a lake where they would drink some of the lake water and i believe itd block their magic powers? Anw so one of the characters (either a twin or a sibling) didnt go cus they were sick so then they got taken by the witch government or smthn like that so later the mc goes to find this witch lady (i think) who teaches him and then they have to cross to this island to rescue the brother and then they walk a path in the sky to leave i read this around 2019-2021 and ik it was in canvas