Arcane Filament

You summon a glowing, magical silk filament that tethers a creature or object in place. A creature must make a Strength saving throw or be restrained. While restrained, the thread also siphons arcane energy—if the creature casts a spell, the caster must make a concentration check or lose the spell. If they fail, you may absorb a small amount of the arcane energy, granting you 5 temporary hit-points.