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.