Chained Hell

Purple flames burst out from your palm and conjure 3 chains that you use to restrain and burn your target(s). 

A creature you cast the spell on must succeed on a Strength saving throw or be restrained by the flaming chains until the spell ends, talking 1d8 fire damage for each chain, at the beginning of each of their turns. A creature restrained by the chains can use its action to make a Strength check against your spell save DC. On a success, it frees itself.

When the spell ends, the chains disperse into dust.

At higher levels: For each higher level spell slot you add another chain.