Warp-blade

The origin of the warp-blade rogues is shrouded in rumor. Did a rogue stealth so hard they slipped into another plane? Did a wizard experiment on some thugs? Were they sent by the gods to punish us for some unknown crime? Who knows. All that truly matters, is the world now has teleporting, logic-defying killers and thieves. That seems wonderful and terrible enough for now.

Warp-Portal

When you select this archetype at 3rd level, using the ethereal essence you possess, you can create a pair of portals to use to travel between.

As a bonus action you create one 5ft portal at your feet and a second 5ft portal at a point you can see withing 30ft for one minute. You can choose to utilize the portal under you upon using this ability. Moving between portals on subsequent turns requires use of a bonus action.

Rules for the portals:

These portals are only connected to each other. If, for some reason, there are other portals using the ethereal plane, your portals will not interact with the other.

The portals must be placed on a solid surface, said surface can be horizontal, vertical or on a ceiling. If the surface a portal is placed on is no longer solid,  both portals cease to function.

You can only have one set of portals at a time.

Only you and the Items you are wearing or carrying may travel through the portals, provided  you are not over-encumbered and items you are carrying can easily fit through the portal.

The portals are intangible for nearly anyone but you, but they are visible.

If a portal is occupied by another creature or object you are shunted to the closed unoccupied space and take damage equal  the amount of feet moved.

You can choose to dismiss your current portals as a bonus action.

Your portals disappear if you are knocked unconscious or move more than 100ft from the nearest portal.

Phantom Walk

At 9th level, you gain the ability to wrap yourself with the energies of the ethereal. As an action, you become partially ethereal until the end of your next turn. You become partially transparent and can move through solid surfaces.  This can be used to free yourself from restraints, or move through solid surfaces.  If you occupy the same spot as a solid object or creature when this effect ends, you are immediately shunted to the nearest unoccupied space that you can occupy and take force damage equal to twice the number of feet you are moved. Unlike the spell "Etherealness" this ability does not allow you to move in defiance of your normal movement restrictions. 

You can use your portals in conjunction with this ability.

Once you use this feature, you can’t use it again until you finish a short or long rest.

Not this time

Starting at 13th level, you can instantly move to one of your portals when about to be hit by a critical blow. When an enemy rolls a critical hit against you, you can use your reaction to teleport away to one of existing portals. If you do not have active portals, you cannot use this feature. 

Once you use this feature, you can’t use it again until you finish a short or long rest.

Warping Strikes

Starting at 17th level, you can move nearly instantly between multiple enemies, striking each one as you go. As an action, you select a number of enemies you can see equal to your dexterity modifier (Minimum of 1),  teleporting to, and attacking each one at advantage. At the end of the  attacks, you can choose to remain adjacent to the last enemy hit, or revert back to your starting location. 

Once you use this feature, you can’t use it again until you finish long rest.