So I did the g-horn quest in rise of iron and the grimoire hasn't popped. I even infuse my reward gjallarhorn into the promotional iron gjallarhorn thinking it might trigger it but it did not. I know it doesn't really affect my grimoire score. But I really like the in depth lore you get from the cards. Any way just wanted to let you know. I don't know if this is a personal problem for me or I'd other players have experienced it. Just a heads up