The Tether

You utter the binding words from the deepest and darkest abyss and you bestow a curse that chains up to 4 people to each other for the casters purpose. Much like infernal contracts and warlock pacts, This curse cannot be broken unless the caster dispels it or the caster dies. 

• Choose 1- 4 targets (can be up to 6 depending on character level). Targets must make a WIS saving throw (up to DMs discretion).
• If saving throw failed, targets will be bound together. One or more targets cannot move more than 35 feet away from each other.
• While cursed, and outside of the 35 feet, the targets must make a Wisdom saving throw (DC 18) at the start of each of its turns. If it fails, targets gets dealt 1d4 necrotic damage per turn unless they return within the 35ft radius.
• While the target is cursed, your (the caster) attacks and spells deal an extra 1d6 necrotic damage to the target.

The caster must dispel or die to end this effect. At the DM's option, you may choose an alternative curse effect, but it should be no more powerful than those described above. The DM has final say on such a curse's effect.

At Higher Levels. If you cast this spell using a spell slot of 8th level or higher, then you can target up to 4 people. If you use a spell slot of 10th level or higher, then you can target up to 5 people. If you use a spell slot of 12th level or higher, then you can target up to 6 people.