when the order of the ghostslayer and the order of the mutant teamed up to destroy a large portal to the shadowfell some members were mentally damaged  (and others psychicaly) many died and the survivors(other than the ones that later became the order of the bloodless) swore a vow to fight all creatures of the shadowfell and those that draw power from it 

Rite of the shadow

When you join this order at 3rd level, you learn the Rite of the shadow esoteric rite (detailed below).

Rite of the shadow Your rite damage is necrotic damage. While the rite is active, you gain the following benefits:

• You have resistance to necrotic damage.
• if you your target has teleported in the minute deal 2 addtinal hemocraft dies of damage 

think like a shadow

Beginning at 3rd level, your ancient order teaches you to move through shadows with thought alone as an action while your in dim light or darkness you can make a dc 16 int check  if you fail take 1d6 necrotic damage if you succed  teleport a number of feet up to your int mod times five. once you fail the check you can not use this ability until you take a short or long rest.

Ethereal Step

Upon reaching 7th level, at the start of your turn, if you aren’t incapacitated, you can choose to magically step into the veil between the planes.

You can move through other creatures and objects as if they were difficult terrain, as well as see and affect creatures and objects on the Ethereal Plane. You take 1d10 force damage if you end your turn inside an object. If you are inside an object when this feature 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 moved. This feature lasts for a number of rounds equal to your Intelligence modifier (minimum of 1 round).

You can use this feature once. Beginning at 15th level, you can use your Ethereal Step feature twice between rests. You regain all expended uses when you finish a short or long rest.

Brand of shadow

Beginning at 11th level, your Brand of Castigation now allows to use your think like a shadow ability to move within 30ft of the branded creature asumming there is dim light or darkness within 30 ft of them 

Blood Curse of the Exorcist

At 15th level, you’ve honed your hemocraft to tear wicked influence from your allies, punishing those who would infiltrate their body and mind. You gain the Blood Curse of the Exorcist for your Blood Maledict feature. This doesn’t count against your number of blood curses known.

Rite Revival

Upon reaching 18th level, you learn to protect your fading life by absorbing your blood rite. When you are reduced to 0 hit points while you have an active Crimson Rite, but don’t die outright, the rite ends and you drop to 1 hit point instead. If you have rites active on multiple weapons, you choose which one ends.