Death by Leeches

You prick your finger and wipe your blood upon a leech, before throwing the slimy worm at a target that you can see within range. The leech multiplies in the air, creating more and more tiny parasites until it forms into a Swarm of Leeches by the time it reaches its mark. The creature must make a dexterity saving throw against your spell save DC. On a success, the swarm instead lands in a random square within 5 feet of the target, where they do nothing until the beginning of your next turn. On a failure, the leeches attach themselves to the creature, making a bite attack.

Once attached in this way, the creature or an ally within 5 feet can use its action to make a DC 10 medicine check to remove the leeches. Otherwise, the target continues to take a cumulative 1 point of piercing damage from the leeches (to a maximum of 5) per turn until the leeches are removed, the duration ends, or you lose concentration. When the spell ends, the leeches dry up and crumble into dust.

On each of your turns, beginning at the turn after you cast this spell, while you maintain concentration, you can direct the leech swarm to use its bite attack (Melee Weapon Attack: +4 to hit, reach 0 ft., one target in the swarm's space. Hit 5 (2d4) piercing damage), move (10 ft., swim 30 ft.), or detach from a target as your bonus action.

You may end the spell as a bonus action.

At Higher Levels.When you cast this spell at 2nd level or higher, you can summon one additional Swarm of Leeches for each level above 1st. The swarms can be directed together or separately as part of the same bonus action on your turn. Additional swarms can share the same space as other swarms and creatures.