I thought it would be an interesting idea to somehow apply the "Extendable" mechanic of walls to the other spell types, particularly Incantations and Attack spells. MW could do this through a mechanic called "Ritual."
The Ritual mechanic would function similarly to the Extendable mechanic. When your mage casts a spell with the "Ritual X" trait, you may immediately search your spellbook for another copy of the same spell, pay the "X" cost specified to "commit" that spell to the ritual and receive a bonus effect, cast and resolve the spell, and discard both cards. Of course, the player could also choose not to pay the Ritual X cost, in which case no additional effect would occur.
Through this mechanic, MW could make the act of casting Attacks and Incantations more engaging and offer more strategic options to players.
For example, I made up some cards that illustrate the idea:
Spiritfire (mana cost = 5) (range = 0-2) (target = object) (type = flame, ritual) (level 1 fire & air school Attack spell)
Attack Dice: 3, Effect Die: 7+ = Burn
If Spiritfire's Ritual cost is paid, it gains the Indirect and Ethereal traits.
Ritual 2
Bestial Fury (mana cost = 5) (range = 0-1) (target = corporeal creature) (type = command, ritual) (level 1 war school & level 2 nature school Incantation spell)
Target gains the Fast, Charge +1, and Melee +1 traits.
If Bestial Fury's Ritual cost is paid, the Target gains an additional Charge +1, Melee +1 and gains the Uncontainable trait until the end of the round.
Ritual 3
Profane Prayer (mana cost = X) (range = 0-1) (target = living creature) (healing, curse, ritual) (level 1 holy school & level 1 dark school Incantation spell)
Remove as many conditions from the target as you wish, paying the removal cost for each one. Then, if Profane Prayer's Ritual cost is paid, redistribute those same conditions onto any creature they may legally affect in the same zone as the target.
Ritual X (X = removal cost of conditions)
I'm not sure 100% about the balance of these prospective cards, but you get the idea. The Ritual mechanic is basically a way of giving players some neat options that allow them to adapt to and capitalize on changes in the arena.
Thanks all, constructive feedback welcome.