Yeah there have been a couple of minor items added recently. The Magic Tome is generic and not anything plot-related (so far, that I can tell). But note that it's a *left*-hand item, so a character can use a one-handed weapon (i.e. for a caster, a regular staff but not a Master Staff) and equip this for an additional stat boost.
Viewing post in Found a new weapon in a crypt
I honestly never thought of it like that, I thought it was it's own stand alone weapon. and while it may not be useful for a pure mage since the Master staff more than makes up for any stat increase, you could give it to a character that uses a Heavy sword that for example is mainly made of dragon bone so you could have a better mixed attacker. You can literally play Robin from Fire Emblem in this game now and I love it.