Guild of the Ghost
Some rogues enhance their fine-honed skills of stealth and agility with the magic of the Ethereal Plane. These rogues include highly specialized assassins, spies, and thieves for hire and those already in the service of a government or large organization. Undetectable, untouchable and notoriously difficult to prepare against, ghosts are exactly what they claim to be.
Phase
Starting at 3rd level, when you use the bonus action granted by your Cunning Action to take the Phase action. When you do so you become semitransparent, you can move through non-magical difficult terrain without expanding any additional movement and can move through non-magical objects and creatures. If you end your turn inside an object or creature, you are immediately shunted to the nearest unoccupied space that you can occupy and take force damage equal to the number of feet you are moved. You can use this feature a number of times equal to your Int plus your Proficiency bonus per long rest.
Blink
Starting at 9th level, when you use disengage action from your cunning action feature, you can disappear, reappearing in an unoccupied space you can see within 30 feet of you. You can use this feature a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a long rest.
Empowered Phase
Also at 9th level, you can now Phase through magical terrain, objects, and creatures without issue such as those produced by Hallucinatory Terrain or a Leomund’s Tiny Hut but not those which extend into the Ethereal Plane such as a wall of force. Additionally, you gain advantage in the next two melee attacks you do if you already haven't.
Supernatural Sense
By 13th level, you've displaced yourself so many times that you've developed an otherworldly sense. You can see into the Ethereal Plane when you are on the Material Plane, and vice versa. In addition, when you gain blindsight it becomes up to 30 feet.
Ethereal Phase
Beginning at 17th level, you've mastered your ability to Phase. When you Phase, you completely disappear into the Ethereal Plane becoming invisible and unable to produce sound. Any damage you take when you Phase is halved. When you Phase, while on a plane of existence that does not have an Ethereal Plane you create your own centralized version of one, allowing your abilities to be used seamlessly as if there was one.