Draining Kiss

You drain the life from those you come into contact with. You kiss a charmed creature or a willing creature. The target must make a Constitution saving throw against this magic, taking 1d10 + your spellcasting modifier psychic damage on a failed save. The target's hit point maximum is reduced by an amount equal to the damage taken. You gain a number of temporary hit points equal to half of the damage dealt rounded down. The target dies if this effect reduces its hit point maximum to 0.

The damage of draining kiss increases by 1d10 when you reach 5th(2d10), 9th(3d10), 13th(4d10), 17(5d10)th level.

You may cast this spell as a ritual. Your target must remain within 10 feet of you for the entire ritual. At the end of the ritual, the target is drained of all of their life essence. They die and you consume their soul. This may garner some benefits (at the consultation of the DM).