Bear with me, this is a somewhat complicated post, but I'll try my best to word it as well as I can.
I more or less had an idea for Clerics (or perhaps even all guilds), where they could acquire a spell that acts as a variant of Shield of Light (or perhaps Manifest Force) - This spell, when cast, would form a layer of mana that acts as a static shield of sorts that absorbs incoming attacks. The difference between this and other spells being that it draws directly from your attunement at some sort of increasing cost, e.g.:
-1 damage - 4 mana
-2 damage - 9 mana
-3 damage - 15 mana
-4 damage - 22 mana
(etc)
This would make it more useful in absorbing multiple weaker hits, but the ability to absorb a few strong hits is still plausible...just, it'll deplete your mana very quickly if you're not careful.
Casting a spell of any kind would interrupt it's flow, and cause it to dissipate; this would make the spell "truly defensive", and while skilled magi can get the most effect out of it, it'd ironically have the most hindrance due to limiting their magic. Whether it be allowed to all guilds or just Cleric, it could perhaps be infused into Osrel Meraud - it'd allow for casts still, and it's potency increased via infusion (rather than initial cast), but the orb's mana would drain dangerously fast due to the spell's nature.
This could also perhaps serve as some form of sorcery (e.g. a mix of SoL / ES), but that's splitting hairs. All the same, thoughts?
