That sounds awesome, but in some instances the higher level spells had there repercusions, you cant just go nuking the sh*t out of a god at any given time, or else, you die and Risk wiping, also the fact that they dont always hit for full damage and cost a !@##@#$!@%!#%@$ Amount of MP really scale it down IMO, but it would be hard to argue if they could implement a system in which the effectiveness of a spell depended on the previous casts, cast numbers, Tier Progression (Thunder, then II, III, Causes IV to have better effectiveness and Damage) and MP regeneration to not lose the said progession in battle youve made with those successive casts.
I see your perspective completely, I'm mainly assuming that this would be a better system than the current one assuming that they are making a new system.
In my mind, this would be great for not making certain spells obsolete, never to be used again by any class. I'd love to see this sort of thing implemented, so long as they scale the tank/melee abilities to work along the same lines.
For instance, tanks get more reactive taunts(after a block, parry or evade, able to perform a follow-up move, melee being able to stun etc after certain moves). I believe this could solve the problem of spike aggro in those circumstances.