Order of the Madman

The Far Realm exists as a total enigma. Even the most dedicated arcanists will learn nearly nothing of it. Warlocks in service to its denizens seldom even learn what their patrons want of them, let alone grasp what the world they inhabit is like. It exists entirely separate from the inner and outer Planes. A few blood hunters, nonetheless, have taken it upon themselves to draw power from it in an attempt to combat the relatively mundane threats found in the abyss and the nine hells. This power never leaves its users unscathed. It twists the mind, warps the body, and tears the soul. 

Rite of the Bizzare

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

Rite of the Bizarre. Your rite damage is psychic type.

This rite deals half the damage rolled on your rite die, but it forces the target to make an intelligence saving throw contested by your Wisdom (insight) check or roll 1d4. On a 1, it becomes stunned, 2, it becomes frightened of you, 3, it becomes charmed by you, and 4, it becomes confused. These effects last until the end of its next turn.

Upon reaching 11th level, any creature you hit with your Rite of the Bizarre  suffers this additional Psychic damage equal to its intelligence modifier, assuming it is positive.

Extra Limb

Beginning at 7th level, your physical form twists from exposure to the eldritch power of the Far Realm.

You gain an extra limb you can use to hold a weapon or shield. This may be a new hand, a tentacle a set of pincers, an amorphous pseudopod, or any thing else You can think of. You may hold as many weapons as you have limbs, but you may only benefit from one shield. When you use your Multiattack, each attack may be with a different weapon. 

You gain another at 13th level, which gives you a third attack when you take the attack action.

Twisted Mind

Upon reaching 11th level, your mind has been permanently warped by the horrors you have delved into in your quest for power. You gain resistance to psychic damage, and whenever a creature uses magic to try to influence your mind, including charming or frightening you, must make an intelligence (arcana) check contested by your Wisdom save. If they win the contest, the effect continues as normal. If they lose, the effect is prevented, and they take 2d8 psychic damage.

Absentee soul

At 15th level, your soul feels no special connection to you body. While you rest, your soul can leave for up to 8 hours. Your soul is invisible, has a movement speed equal to yours, has truesight to 60ft, and the only action it can take is to return to your body. Your body while your soul is absent is incapacitated and has an AC of 0.

Flayed Mind

Upon reaching 18th level, your mind has twisted to the extent you can fully understand the power of the Old Ones. Choose a spell of each level up to 5th from the warlock spell list. You may cast them at base level at will without any material components.