Conjure Threadlings

Weaving Strand into living beings, you create 3 writhing, leech-like creatures next to you made of Threads. Each Threadling shares your movement speed and acts either at the start of your turn or directly after it.

When within melee range of a creature, a Threadling can make a melee spell attack against the target. On a hit, it latches itself onto the creature and begins to siphon its hit points. At the beginning of the target's turn, the Threadling deals 1d10 necrotic damage, and you are healed for half of the damage dealt. Multiple Threadlings can attach to one target.

If a Threadling is not attached to a target by the end of its movement, it can be targeted by an enemy attack. It has 1 hit point and an Armor Class equal to your spell save DC. If a Threadling successfully attaches to a target, it can only be removed by having a creature allied to the target hit the affected target with an attack, or until the duration expires. Multiple outcomes can occur:

• If the attack roll is lower than the Armor Class of both the Threadling and the target, nothing happens.
• If the attack roll is higher than the Armor Class of the Threadling but lower than the target's, the Threadling is destroyed, and the target takes half of the damage that the attack would have caused. 
• If the attack roll is higher than the Armor Class of both the Threadling and the target, the Threadling is destroyed, and the target takes the full amount of damage from the attack.

Using a Higher-Level Spell Slot. The number of summoned Threadlings increases by 1 for each spell slot level above 3.