So in Oblivion I have made a spell which can deal 2,800 damage. This spell works by the following effects;
100 Weakness to magic
100 Weakness to ice
100 Weakness to shock
100 Weakness to fire
100 drain health
100 damage health
100 fire damage
100 frost damage
100 shock damage
I should warn that this spell has an absurdly high magic cost, if you wish to make this spell but do not have the mana to cast it then first try removing the damage health effect from it. If that does not work then slowly cut down on the elements until it is enough. Do not lower the weaknesses or that will massively weaken the spell.
How it works;
[spoiler]The weaknesses in Oblivion stack, so that means that the weakness to magic will double the effectiveness of the weakness to fire etc. That then stacks again in order to make each single element effect deal 400 damage.[/spoiler]
[spoiler]The drain health is temporary, but it is cheap due to that. That means you can throw it on most spells and it will do the damage to the enemy until the effect wears off. But if you do enough damage to kill the enemy, they are dead even if the effect wears off. [/spoiler]