Dagger of a Mind

You can choose one humanoid of your size within your line of sight. When they look in your general direction (up to 6ft away in any direction) you can cast the spell to enter the mind of the target. They must succeed on an Intelligence saving throw equal or higher to your spell save DC.
On a successful save, the creature develops a headache and a disadvantage on Dex and Con saves. It can no longer be surprised.
On a failed save, the caster enters the mind of their target and gains full control of their body. The caster is at liberty to take any action they know the target is capable of. They gain the target's proficiencies and knowhow of attuned items. The caster can also perform their own cantrips. The creature under the spell can make an Int saving throw every turn during combat or every 18 seconds outside of combat.
The spell lasts until the caster drops their concentration(max. 5 min) or the creature succeeds on a saving throw.