Contract

You and a willing creature create a magically binding contract. When you cast spell, decide the terms of the contract. They can be as vague or specific as you wish, as long as both participants genuinely agree. If a creature is coerced or forced into the contract, the magic will not take hold and the spell is wasted. When you create the contract, choose one of the effects from the list below for each creature. Any creature that breaks the contract is immediately subject to the chosen effect, and the spell then ends. 

Brand- The creature that breaks the contract is branded with a permanent mark decided at the spell's casting. 

Curse-The creature that breaks the contract has disadvantage with rolls made using one stat chosen at the spell's casting. After one week, and every week afterwards, the creature can make a wisdom, charisma or intelligence saving throw. On a success, this effect ends.

Spellblock- All creatures have advantage on saving throws against spells cast by the creature that breaks the contract. After one week, and every week afterwards, the creature can make a saving throw using their spellcasting ability modifier. On a success, this effect ends.

Any negative effect from this spell can be dispelled by Remove Curse or similar magic.