The path for the shamed, the marter, the criminal, the hateful. Grow your hearts longings into a demon that will tear at your mind but through stealing your self and facing it head on your sins will be used to forge your future success turning you from a fool to the wisened veteran or will you fall to insanity and become the demon in your heart you fear so much?

Monks that walk this path are seen as monster or beings that should not be associated with to the point even gods of good see them as Demons that should be destroyed when in truth they are the discarded, the beaten, the broken, nothing more than people who have lost everything and wish for nothing more than to burn the heavens thus they mad they are deadly and they must come to terms with who they have become for they are a walking disaster in flesh form.

This is a subclass that focuses on the spiritual and mental side of the monk this will have more to do with wisdom then strength. 

Demonic Form

Demonic Form 

Transform your ki and life force into that of a demon making you strong and deadlier than ever before but be aware that you may lose your self.

At Level 3 you can perform -

Blood Armor - As a reaction to being attacked via a material attack, or spell attack spend 1 Ki point and roll 1d4 add the number to your AC till the start of your next turn and take the number you rolled as damage. This can be announced after the attack roll but before the damage roll.

Demonic Presence - Spend 2 Ki points and for a Bonus Action you can affect a 15ft radius around you with hallucinating effect based on the sins of your hart all creatures in the area must make a Wisdom saving throw. DC of this effect is equal to 8+Wisdom modifier all creatures that fail this become hallucinogenic and see you as a demon that will eat their souls and believe the floor is made of blood and bones that is holding them in place, the creatures are considered restrained. A creature that succeeds is frightened till the end of there next turn as you only apper bigger and slightly more evil to them.  

At Level 6 you can perform - 

Blood Step - Your wrath for an enemy must be seen too thus chase them through the void and all nine hells and trace them through the bloody wounds they inflicted on you. Spend 6 Ki points to create a portal from your blood strate to a creature that hurt you within 1000ft or into to the same plain (note the portal will not place you next to the enemy if you are hopping realms and could end up a long way from your target). The creature you target must have done damage to you within the last 24 hours. The blood portal lasts for 5 minutes.

Manifest Sins -  The sins and demons of your hart form into a weapon that represents your charters personality for 2 Ki points last for 1 minute. This weapon attack is d20 + DEX modifier + WIS modifier and deals damage equal to your unarmed strikes (note damage from this weapon cannot be blocked or infective) + 1d4 necrotic damage.

At Level 11 you can perform -

Demonification - Your being transforms into that of a demon with a visual representation of your greatest sin for 10 Ki points lasts 1 hour. In this, form your movement speed is 0 but you can instead teleport up to 60ft as your movement and dash you can take 1 creature of 1 size larger than you with you, you are also classified as floating, any creature that sees you must make a Wisdom saving throw or be frightened DC equals 8+ WIS modifier and proficiency, plus flurry of blows now costs nothing during the demonification.

Demonic Spellcasting

You have meditated and gained insight from the demons in your heart and now you can manipulate them in a way that allows you to perform tricks of an arcane nature and twist the nature of those who are dead and living if only in a slight manner.

Cast spells via the demonic forces brewing in your hart. Unlike other class, the spells you can cast is limited you can only spend up to 6 Ki points on a spell. 

Spell Save DC = 8 + your proficiency bonus + Wisdom modifier

Spell attack modifier = your proficiency bonus + Wisdom modifier

Spells cost 1Ki point higher than there spell level. E.g 1st spell LV = 2Ki point, 2nd spell LV = 3Ki points, Etc

SPELLS	SPELL LEVEL	LEVEL OBTAINED	KI POINT COST

False Life, Ray of Sickness

1

6

2

Blindness/Deafness, Gentle Repose, Ray of Enfeeblement

2

6

3

Animate Dead, Speak with Dead, Vampiric Touch

3

9

4

Blight, Shadow of Moil

4

13

5

Danse Macabre, Enervation, Negative Energy Flood

5

18

6

Demonic Thoughts

Speak to the sins in the heart of another driving them mad in fear or willing make it so your words carry weight in gold in their ears for your speech comes from the demons of your own hart that you have mastered.

Your Tongue of the Sun and Moon can now be used to charm, or fear an opponent if you spend 3 ki points. The target gets to make a saving throw against your Spell save DC. If they succeed then you are either feared or charmed of the creature in a backlash. 

Marble Heart Realm

Your heart is corrupt but your will is strong turn your inner turmoil into a realm of sin that you unleash onto the world that will obey your call

For 17Ki points transform 3000ft into the realm of your harts sins making it impossible for any creature to hide from you or leave this space without your permission plus you can command the space to attack up 10 creatures or 1 creature 10 times per attack action dealing 1d8 necrotic damage, you can also cast all spells from Demonic Spell Casting for 1 Ki point, less. Gain back 1 Ki point for each creature killed within the area of effect.

Lasts as long as you are awake.