6th-level Necromancy

Casting Time: 1 action
Range: Self (20-foot-radius sphere)
Components: V, S, M (a crystal rod carved with necromantic runes worth 500 gp)
Duration: Concentration, up to 1 minute
Class: Cleric, Sorcerer, Warlock, Wizard
Sourcebook: L’Arsene’s Ledger

You spew a cloud of crimson smoke from your mouth, which gathers in a 20-foot-radius sphere centred on your space that lasts for the duration, heavily obscuring the area. Each creature other than you that starts its turn in the cloud or enters it for the first time on its turn must make a Constitution saving throw, taking 5d8 necrotic damage on a failed save, or half as much damage on a successful one. For as long as the cloud lasts, you can use a bonus action to move it up to 20 feet in any direction.
A humanoid reduced to 0 hit points by this damage immediately dies and returns as a zombie under your control. Zombies created by this spell have immunity to its effects. You can control a maximum of three zombies at the same time. Any created beyond this number are hostile to all living creatures. In combat, zombies take their turn immediately after yours. Zombies under your control obey your verbal commands (no action required by you). When the spell ends, zombies created by the spell crumble to dust and are destroyed.
At Higher Levels. When you cast this spell using a spell slot of 7th level or higher, the damage increases by 1d8 for each slot level above 6th.