Visions of the Cosmos
Starting at 1st level, your connection to the Astral Sea grants you an innate knowledge of the planes. You gain proficiency in Planes (Knowledge), or expertise if you already have proficiency. In addition, you add your Charisma modifier to any Planes (Knowledge) checks you make.
Silver Vitality
At 1st level, the stars grant you some of their power. When you take a long rest at night, you do not need to sleep. But, you can only do light activity, such as taking watch or reading, while taking this long rest.
Touch of the Void
Starting at 6th level, you can open a rift to the furthest reaches of the Astral Sea. Make a melee spell attack against a creature within reach. If the attack hits, the creature must make a Constitution saving throw. On a failed save, they take 4d10 + your Sorcerer level force damage, or half as much on a successful save.
You can use this feature once, and gain the ability to do so again when you finish a long rest or expend 2 sorcery points to do so again.
Crossroads of the Universe
Starting at 14th level, you learn the Plane Shift spell, which does not count against the number of sorcerer spells known. When you cast Plane Shift, the range becomes 10 meters.
Star Drifter
At 18th level, you learn the Astral Projection spell, which does not count against the number of sorcerer spells known. You can cast Astral Projection without needing material components.
While in the Astral Sea, your silver cord cannot be severed involuntarily, and you gain a movement speed equal to your Charisma score.