Rogues of this archetype are individuals who have at some point been affected by the Astral Sea. As a result, you have gained the ability to tear open portal like rifts which you use to move around the battlefield with ease. Either to get the drop on an opponent hitting them when they are least expecting it or to teleport into the shadows never to be seen again.

Astral Step

Starting at level 3, You have learned from your past experiences with the Astral plane and have the ability to open rifts in the natural world to get from place to place and to surprise your enemies with devastating attacks. You are able too teleport 30 feet as a movement action. The distance you can teleport increases by five feet at level 7, 11, and 15. You are able to teleport this way a number of times equal to two times your proficiency bonus. You regain all expended uses when you finish a long rest.

Hidden Teleport: If you teleport to an area in dim light, darkness or concealment, you have advantage on your stealth check.

Sudden Strike: You teleport right beside your enemy and strike, catching them off guard. You have advantage on a single melee attack for the duration of your turn after teleporting.

Planar Butcher

Planetouched

At level 9, The effects on your body from your experience with the Astral Sea amplify and manifest in these changes. 

Timeless Self: The flow of time from the Astral Plane has permanently effected you and causes you to age more slowly. For every 10 years that pass, your body ages only 1 year.

Astral Vision: Your eyes lose all color and now reflect the stars and the planar bodies of the Astral Sea. You can see normally in darkness, both magical and nonmagical, to a distance of 60 feet. If you already have darkvision from your race, its range increases by 30 feet.

Planar Resilience: You gain resistance to force damage as you feel empowered from the Astral Sea.

Dimensional Rebound

Starting at 13th level, you may as an action cast the spell Dimension Door. Following that as an bonus action on your following turn you may choose to teleport back to your original location from when you first cast the spell. You may use this once before you must finish a short or long rest.

Cleaving Rift

Starting at 17th level, when you hit a creature with an attack, you can use this feature to tear a rift open inside of your targets body. The planar rift rips away at their body dealing 6d12 force damage and it must make a Strength saving throw against 8 + your proficiency bonus + your Intelligence modifier. On a failed save, the rift knocks the target prone.

You can use this feature once per short rest.