The Seven Altars seems bugged, I visited all seven and got nothing, and it doesn't update your progress either.
Did you let the Gods' feed upon you?
That's much later isn't it? What does that have to do with the altars?
During the dialogue on the Nameless Isle, you're given the option to let the majority of the seven to feed on you when praying. They take a source point and AFAIK try to 'curse' you in some (annoying) way. Like, Rallic will permanently blind you to make it easier for his champion to beat you.
I got "an apple a day" and "a song unsung”.
I beat the game before patch 3 though. Maybe they are broken after patch 3
Quite possible; it does seem as though some achievements were rendered broken after a certain patch. Unfortunately for me, I was playing a custom character for my first campaign on tactician mode and it took quite a while... Probably missed the window of opportunity to get it until they fix it again.
I've gotten some of these so I wouldn't call them 100% broken.
I'm not; they're listed as definitely buggy or broken as I myself was unable to obtain them after numerous game completions and other users reporting inconsistencies with their acquisition.