I just finished watching a terrible series based on the King Arthur legends (I think it was called Camelot, but I'm not sure) and an idea occurred to me. In this series, Merlin describes the use of magic have a real physical, emotional and psychological cost attached to spells. The greater the magnitude of the spell, the greater the "cost" will be. I thought that this would be fun to implement in Morrowind. For example as fire damage and/or range increases, a proportional amount of the PC's health is damaged to the point where an apocalyptic fire damage spell will kill not just the enemy but the PC as well.

I think that it would add a bit of game balance for those who are using MCP increase magnitude module and might be just fun for everyone else. This seems to be somewhat impractical to do in game as the negative spells cost maigicka just as the more positive effects do as well. In addition, it can potentially lower the effectiveness of the spell especially if the PC is unschooled in destruction based magic.

My real question is this: is there a way to add a type of physical cost to the use of any spell without increasing the amount of magicka required or changing the school of magic that the desired spell is in (i.e. Summon Golden Saint stays in the College of Conjuration and is not altered to say the College of Destruction because of the associated cost). Also, the effect of the cost would need to be displayed in game in the magic menu, spell merchants and while creating a spell.

So, any ideas?

(edit: to give an in game example of what I am talking about, look at the mantle of woe. The mantle allows any player to be come the best summoner in Vvardenfell at the cost of being weak towards normal weapons, taking sun damage during the day while outdoors and having everyone pretty much hate your guts. Now imagine that as a castable spell while only the fortify effects require the magicka.)

You could easily add drawbacks to something like scrolls, where you can specify how much they cost and what they do. It would be a lot more difficult with regular spells. You'd probably need one of the extenders to pull it off.