Warriors who have studied what happens to souls after death can often find themselves delving deep into the Ethereal Plane for answers. This research can grant them insight to incredible powers and forge strong allegiances with creatures from this plane. An Ethereal Knight harnesses powers from this plane to strike powerfully with force or be hidden scouts in the Ethereal. Whether they are members of religious orders, secret military organizations, or special operation task forces, these warriors are silent, deadly, and even be right behind you.

Incorporeal Defenses

You are slightly in phase with the Ethereal Plane and can occasionally positional yourself in between the Material and Ethereal.  When you take nonmagical bludgeoning, piercing, or slashing damage you can use your reaction to gain resistance to nonmagical bludgeoning, piercings, or slashing damage until the start of your next turn.

You can use this feature a number of times equal to your proficiency bonus and regain all expended uses at the end of a long rest.

Ethereal Strike

Your attacks harness a powerful energy from the Ethereal Plane.  Once per turn when you hit a creature with a weapon attack you may deal an additional 1d6 force damage.  This damage increases to 1d8 when you reach 10th level.

Spectral Scout

Starting at 7th level, you can perform a 10-minute ritual to send yourself to the Ethereal Plane for a brief time.  At the end of the ritual, you are teleported to the Ethereal Plane for one hour.  While on the Ethereal Plane, you can see and hear the plane you originated from, which is cast in shades of gray, and you can't see anything there more than 60 feet away. You can only affect and be affected by other creatures on the Ethereal Plane. Creatures that aren't there can't perceive you or interact with you, unless they have the ability to do so.

At the end of the hour or when you choose to as a bonus action, you are returned to the location where you performed the ritual.

Intangible Warrior

At 10th level, you have learned how to spend short periods of time positioned between your originating plane and the Ethereal.  As a bonus action, you become partially intangible and ghost-like for one minute.  In this form you gain the following benefits:

• You gain a flying speed equal to your walking speed and can hover.
  

• You can roll your Ethereal Strike damage die a second time when you hit with a weapon attack.
  

• You can move through creatures and objects as if they were difficult terrain, but you take 1d10 force damage if you end your turn inside a creature or an object.
  

Once you have used this feature you cannot do so again until you have finished a short rest or long rest.

Reclaim Potential

Beginning at 15th level, whenever you complete your Spectral Scout ritual, and return to your originating plane, you can bring a ghost back with you.  The statistics for which are in the Basic Rules.  The ghost gains a bonus to its Armor Class and attack rolls equal to your proficiency bonus.  It obeys your verbal commands (no action required) and remains in your service until the end of your next long rest, where it returns to the Ethereal Plane.

Once you have used this feature you cannot do so again until you have finished a long rest.

Ethereal Colosseum

Starting at 18th level you have unlocked the ability to send yourself and a challenger into a spectral arena.  As an action, you can force a creature within 60 feet of you to make a Wisdom saving throw.  The DC for this saving throw is 8 + proficiency bonus + your Constitution modifier.  On a failure, you and the creature are teleported to the Ethereal Plane until the end of your next turn.  On a success, you are teleported to the Ethereal Plane until the end of your turn.

You can use this feature a number of times equal to your proficiency bonus and regain all expended uses at the end of a long rest.