balance – Is an item that reinforces the magic of a magical school overwhelmed?

I play with the idea of ​​giving a magic wand to a player, and this wand would allow him to cast all necromancy spells one level higher if the spell is cast with a higher cast slot (eg, vampire touch, disease beam) ).

I have not seen a similar article so it's hard for me to sort it out. I am satisfied with this article, which has unusual / rare properties.