Spirit Twin

 Spirit Twin sorcerers are usually the result of a failed attempt to reincarnate as someone else. Rather than forcing the previous soul out of the body, the invading spirit merges with the current soul, resulting in them gain the ability to cast spells, and a new voice in their head, though most could probably do without the latter.

Soul Bound

You and your spirit twin have reached a new level in your bond few ever have before. When you use your Ethereal Projection ability, your spirit twin appears with an additional hit points equal to your level+your Spell Attack Bonus and can cast any spell you know that is 5th level or lower. It can cast spells with a total combined spell level of 10 or lower. You can also use Ethereal Projection three times before needing to rest. In addition, any creatures under the effect of your Phantasmal Transmutation ability have a 30 foot fly speed and immunity to bludgeoning, piercing, and slashing damage. They also no longer gain weakness to Force, Radiant, and Necrotic damage.

Spirit's Insight

As your soul is intertwined with another spirit that hasn’t or cannot pass on, you can use that spirit's knowledge to learn about a monster. As an action, you may make a Charisma check equal with a DC equal to 16 + half the creatures CR(rounded down) - half your level(rounded up). On a success, you can ask one question about the general abilities of the monster, such as “Is it strong?” or “Does it have any weakness?”. The spirit is not obligated to say specifics, such as what it is weak to or what exactly “strong” means. You can use this feature a number of times equal to your proficiency bonus. The number resets after a short or long rest.

Inherited Memory

In the past, your spirit twin had magic, and now, you can wield their power. You have advantage on death saving throws. In addition, you gain 1 cantrip of your choice from any class. They count as sorcerer spells for you, but do not count against the number of sorcerer spells you know.

Phantasmal Transmutation

You learn to use your spirit twin’s connection to the Ethereal Plane to your advantage in combat. As an action, you can cause you and two willing targets within 10 feet and yourself to take on a spectral appearance for 1 minute. During this time, those under the effect have a flying speed of 10 ft, can hover, and resistance to bludgeoning, piercing, and slashing damage from non-magical attacks and become weak to Radiant, Necrotic, and Force damage. You can also move through creatures and objects as if they were difficult terrain. If you end your turn inside a creature or an object, you take 5(1d10) force damage and are immediately forced out into the nearest unoccupied space, taking an additional 5(1d10) force damage for each 5 feet needed to be moved to reach this location. If you are flying when the effect ends, you drift towards the ground at a more controlled rate and take half fall damage. You can do this a number of times equal to your proficiency bonus.

Twin Projection

Your ability to use the power of your spirit twin has grown to a point where you can call upon them for help. As an action, you can cause your spirit twin to emerge from your body for 1 hour. Your spirit twin in this form uses the statistics of a ghost. It can understand all languages that you do, and has a bonus to its AC equal to your Charisma modifier. The projection takes its turn immediately after yours. As a reaction when you take damage, your spirit twin can choose to swap places with you and take the damage instead provided the roll still beats the spirit twin's Armor Class. The spirit twin returns to your body when it reaches 0 hit points or you recall it back to you as a bonus action. If you do this before your spirit twin reaches 0 hit points, you gain temporary hit points equal to the remaining hit points your soul twin had. These hit points disappear at the same time your spirit twin would have if he had stayed around. You can do this one time and need to take a long rest before you can do this again.