The Wizard's Contract

This spell makes an binding agreement between 2 people. It allows the usage of 1 spell the other person, wouldn't be allowed to perform normally that is in the wizards spell book. But, it comes with a few catches.

Rule 1 : If the one with the contracted spell uses it for anything improper or points it at noncombatants. The contract is destroyed.

Rule 2 : If the spell is offensive and the spell is used on anyone innocent or noncombatants, the spell backfires and hurts the user.

Rule 3: You can only have 1 person contracted at a time.

Rule 4: If by chance the contracted spell is used on the original user. The spell turns back on the contracted one with 3 times more usual damage.