You shoot a ray of dirty grey energy that coruscates between you and one creature in range that isn't a construct or undead. Make a ranged spell attack; if you hit, the ray drains some of the target's strength and transfers it to you. The ray lasts only an instant, but its effects persist for the duration of the spell. While it lasts, at the start of each of the target's turns, it suffers 3d10 necrotic damage, the target has disadvantage on all Strength attacks, checks and saves, and you gain advantage on all Strength attacks, checks and saves. At the end of each of its turns, the target can make a Constitution saving throw to end the effect.