Binding Strike

The next time you hit a creature with a weapon attack before this spell ends, you deal an extra 1d8 force damage and cause a spectral tether to appear between yourself and the creature. You decide it's appearance and if resembles chains, vines, or otherwise. For the duration, the creature must make a Strength saving throw whenever it attempts to move further than where it began it's turn away from you, being knocked prone on a failure. A creature more than one size larger than you has advantage on this saving throw, and ends the spell on a success.

At Higher Levels. If you cast this spell using a spell slot of 2nd level or higher, the damage increases by 1d8 for each slot level above 1st. Additionally, when cast with a spell slot of 3rd level or higher, only creatures two sizes larger than you have advantage on the saving throw.