Some improved mana shield spells:

Enhanced Mana Shield:
Creates a shield that absorbs damage by using the caster's mana. Blocked damage DOES NOT ignore Armor and Armor Types.

Impervious Mana Shield:
Creates a shield that absorbs damage by using the caster's mana. If all damage is blocked it also blocks secondary effects. Blocked damage ignores Armor and Armor Types.

edit: Please mark as awaiting update while I fix the formulas.

Notes:
Impervious mana shield does not block the stun from bash attacks.
Impervious mana shield has side effects such as units losing attack orders on the target when it blocks damage.

Removed Impervious Mana Shield due to it being too glitchy

edit: I've thought of some more mana shield spells to add: Please mark as awaiting update until I add them.