Base Class: Rogue
You have gained the ability to phase into the ethereal plane to gain the upper hand on your enemies, and keep yourself out of danger. With in this archetype, your phase-walking ability gains strength as you gain levels.
Phase-Walk
When you choose this archetype at 3rd level, you gain the ability to temporarily phase out of your current plane of existence. This ability can be maintained up to a minute, provided you don't lose concentration. You may use this ability a number of times equal to your proficiency bonus, all uses recharge on a long rest.
Whilst phase-walking you appear as a distorted semi-translucent spectral version of yourself, whilst using this ability, enemies have disadvantage on attack rolls made against you. (Unless the enemy has blind, tremor or true sight). Similarly, whilst phase-walking your attack rolls have advantage against enemies. However, once you make an attack, you are detected more easily, thus enemies no longer have disadvantage against you, until your next turn.
Attacks made whilst phase-walking qualify for sneak attack, provided the standard requirements are met. (ranged or finesse weapon)
Ethereal Guidance
Also at 3rd level, you have discovered that the visions you experience are of alternate versions of yourself, and you have learned from their choices. As a free action, you may choose to reroll any dice roll after seeing it's outcome. You can use this ability a number of times equal to your wisdom modifier (minimum 1) per short rest.
Evasive
At 9th level, you become more in tune with your phasing abilities, whilst plane-walking, your attack rolls no longer negate an enemy's disadvantage against you.
Ethereal Vision
At 13th level, you gain true sight whilst phase-walking.
Defensive Phase
At 17th level, you can use your reaction to phase out of the way of an oncoming attack, expending a use of you phase-walk feature in doing so.
Using your reaction, you disappear in front of the attacker, you must roll a dexterity saving throw, if the total is higher than the original to hit total, then this is considered a success and you completely evade the attack. On a failure, you take half damage. You can use this ability once per short rest.