Whispers of the Blood

In an inaudible dirge you call to the life essence of another creature inviting it to strengthen you. The target must make a Constitution saving throw. The target takes 4d8 necrotic damage on a failed save, half as much on a successful save, and you gain temporary hit points equal to the amount of necrotic damage dealt.

Other creatures are unaware you are casting a spell unless they are within 5 ft of you, or have the Observant Feat.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d8 for each slot level above 3rd.