You create two rays of necrotic energy and hurl them at targets within range. You can hurl them at one target or several.

Make a ranged spell attack for each ray. On a hit, the target takes 2d6 necrotic damage.  On a critical hit, these rays deal no additional damage, instead sucking the strength from their targets, dealing 1 point of strength damage with a critical. 

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, you create one additional ray for each slot level above 2nd.