MonkeyDM
Level 3 Conjuration (Osteomancy) (Sorcerer, Warlock, Wizard)
Casting Time: Action
Range: 60 feet
Components: V, S, M (a calcified bamboo stick)
Duration: Concentration, up to 1 minute
Massive bone spikes sprout under up to four creatures on the ground of your choice that you can see within range. They must succeed on a Dexterity saving throw or take 3d10 Piercing damage and be impaled by the spike, have the Restrained condition and be held aloft 5 feet in the air for the duration. A creature Restrained in this way takes 1d10 Piercing damage at the start of each of its turns.
A creature can use its action to make a Strength (Athletics) check against your spell save DC, breaking the bone spike and freeing itself on a success.
Using a Higher-Level Spell Slot. The damage (both initial and ongoing) increases by 1d10 for each spell slot level above 3.