Charm Deity

This spell is renowned as one of the most powerful charming spells in existence. With this spell, this allows you to charm any god onto your side for a short time period. Even if this deity wants to kill you, this spell will turn him into the most tolerable, merciful, and kind of people that will undoubtedly aid in your cause.

During this time, any deity charmed with this spell for the certain duration has disadvantage on all Charisma and Constitution saves, cannot make any actions, cannot cast any spells, and (unconsciously) feels the need to do nothing of importance during this time period. 

The deity is under the charmed condition for a max of 5 minutes. Each minute the deity can roll a will save (Con) but with disadvantage to regain his/her senses. 

For example, a wizard can cast a tenth level spell or higher without the legitimate approval of Mystra. Instead, an spell caster can cast this spell to hinder Mystra's senses and decision making from keeping the spell caster from casting this spell. In this circumstance, Mystra would not even be able to stop the caster when under this heavily charmed state. 

Not only can this spell work with a deity, but can apply to any divine-related being.