Everytime you get a character go back to the place on where you find them like for example when you unlock nanami keep going right and you will see the temple and minayo will give dragonbane or in artolia when you get arngrim go back there and go back to his room and you will find dragon slayer or belenus when you go to the maids room and youll find a flower or with lewellyn keep going right until you reach the forest and you find a pendant also with other characters

P.S.:if you send the character that could give his item to you to the gods before getting the items... well you wont get the item that the character would give you so get the item befor sending the character to the gods