Base Class: Sorcerer
Blessed with an instinctive knowledge of bones and bone-related things, Marrowmancer sorcerers literally manipulate the fabric of bones to wield their magic. Bones are their bread and butter. Their boneter. One may even say, the bones are their money.
Bonesense
Starting at 1st level, you have an innate ability to sense the location of bones. If there is a creature with bones within 60 feet of you, you know the specific direction that creature is in as well as its creature type. You do not know the distance it is from you, nor does this function as any sort of blindsight.
Jointivation
Starting at 1st level, your innate understanding of how bones think and feel allows you to trigger joints even when their owners don't want it. As an action, you can make any number of creatures within thirty feet of you make a strength save DC against your spell save modifier. If they fail, you can move them in 5 feet any direction or knock them prone. A creature may fail this save voluntarily.
After you use this feature, you can't use it again until you finish a long rest
Bone Box
At 6th level, you gain the ability to call forth a big box, made of bone. You can spend 3 sorcery points to create either a Large or Medium box in an unoccupied space on the ground within 30 feet of you. On following turns, you may use a bonus action to move the box up to 5 feet. If it touches the space of another creature, that creature is knocked prone and pushed 5 feet away from the box. If the box is Medium, the creature also takes 2d6 bludgeoning damage. If the box is Large, the creature takes 3d6 bludgeoning damage instead.
Roll the Bones
At 14th level, you can suck the magic out of any bones, not just your own. For any spell that doesn't require material components of a specific value that are consumed, you may use bones as the material component of the casting (even if the spell normally doesn't require material components). A spell requires 1/2 of the bones of a normal creatre per spell level to cast. When you do so, the bones are dried out and turn to dust.
When you use bones this way, you may reroll any number of damage dice on the spell. You must use the new roll.
Bonenado
Starting at 18th level, You can spend 6 sorcery points as a bonus action to summon a whirlwind of bone shards in a 20 ft radius around you. Movement speed of all other creatures in that radius is halved, and any creatures you choose make constitution saving throws against your spell save DC at the beginning of their turns or take 2d8 magical bludgeoning damage, or half as much on a successful save. Whenever a creature with bones dies in this radius, increase the damage by 2d8.
The whirlwind lasts 1 minute. It ends early if you are incapacitated, if you die, or if you dismiss it as a bonus action.