"Monks are very much used to learning how to deal with all sorts of enemies. From the big to the small, from the thick to the thin. But has one every considered using our enemies strengths against them?

Most people know this is other ways of study, whether it being using your enemy's ki against them or making them underestimate you. But in this way of study, there is a sense of the mystical and magical. No spells involved here, just a connection to the ethereal plane unlike any other.

We are teaching you how to use your body as a weapon that can't be hurt by swords, axes or daggers. Because, if you can't get hit, how are they going to stop you?"

- Nicholas Attazen, founder of the Way of the Spectre

 

 

Spectral Hand Technique

At 3rd level, you gain the ability to hit ethereal beings and other ghostly beings that normally avoid melee attacks. Also, the melee attack you use for bonus actions from Martial Arts slows opponents for 10 feet of movement for one turn, even if it misses.

Also, all attacks against undead creatures gain a +2 to the attack and damage rolls.

Ethereal Grapple

At 6th level, as an action, you can attempt to grapple one creature from a distance (using Dexterity instead of Strength). This grapple can affect flying creatures or ethereal creatures within a 20 ft. radius.

Half Spectre

At 11th level, you can enhance your dodges and attacks using your connection to the ethereal. When using Deflect Missiles, you no longer have to use a Ki point to make a ranged attack (20/60 feet) with the weapon or piece of ammunition you just caught. 

Also, once per long rest, you can choose to be immune to one melee attack before the damage roll is stated (as a reaction), changing part of your body to ethereal.

Halt at the Threshold

Once per short rest, as a bonus action, you can target one friendly creature within 30 ft of yourself. If the creature is not currently possessed, it has advantage on saving throws to avoid being possessed for 1 minute. If the creature is possessed, the entity possessing it must make a wisdom saving throw at the beginning of each of its turns for 1 minute. On a failure, it exists the possessed creature in an adjacent, vacant space, and cannot possess the same target again for 24 hours.

Full Spectre

At 17th level, as an action, you can spend 5 ki points to turn into an ethereal version of yourself, which last for a number of rounds equal to half your monk level (rounded down). While being full spectre you gain with immunity to non-magical piercing, slashing, and bludgeoning damage, and all sources of magical damage is halved. Weapons you have or use don't do damage while full spectre, as they are also considered ethereal.

With every melee attack that you do while being full spectre (whether a miss or a hit), the enemy must make a Constitution saving throw. If they fail, they take an extra 2d10 necrotic damage.