The Corrupted

You gain the curse of an ancient evil whether it is from a deal made or a relic found a curse slowly corrupts the body and mind of the creature. It allows you to channel the power, but not without cost. The relic you have or rune you have binds you to your choice of Beshaba, goddess of misfortune, Cyric, god of lies, Malar, god of the hunt, Talona, goddess of disease and poison, Talos, god of storms, or Umberlee, goddess of the sea. You learn to channel the energy of the gods but it changes your soul, mind, and body forever becoming the vessel of the gods.

Channel Connection

At 3rd level, you gain the ability to channel the power of your curse for 1 hour, but take 2 necrotic damage per fighter level. You gain a resistance to necrotic damage. Your speed gets +10. You have advantage on attack rolls while you are not wielding a weapon and you can cast Eldritch Blast at you fighter level with your god's respective elemental damage. You gain another use at 5th,  7th, and 12th level.

At 18th level, there is no longer a restriction on how many times you can activate this.

Strength of the Corrupt

At 7th level, as your connects strengthens so do you. While Channel Connection is active you deal an additional 4 damage when making an unarmed melee attack and the target must succeed on a constitution saving throw (8+proficency+con) or takes 1d4 per fighter level. You gain an additional use of Channel Connection.

Tuned to the Corruption

At 10th level, you learn about some of the powers of the evil that inhabits you. As a bonus action on your turn while Channel Corruption is active, you may touch a creature and have it make a Constitution saving throw (8+proficiency+con). If the creature fails it falls under the same curse you have but you have some control over that creature. You may have the creature make an attack on any creature or make any simple actions for the next hour that would not have the creature obviously harm itself. You may only have one creature under your control at a time.

The more you give into the corruption the more you are able to tap into the ancient knowledge. You gain a proficiency in History and Arcana checks

Wicked Whirlwind

At 5th level, the power inside of you hungers for the pain and death of as many as possible. While Channel Corruption is active, whenever you make an unarmed attack on an enemy roll percentile dice if you get 25% or lower you may make another attack an enemy. This effect stacks but for each attack, but for each attack past the first instance the probability is divided by 2. 

• Level 10: change to 50%
• Level 15: changes to 75%

Complete Corruption

At 18th level, the curse has completely taken over your body. If your alignment is not Chaotic Evil it changes to become Chaotic Evil. You can activate Channel Connection without the damage and as many times as you want by meditating for five minutes. While Channel Corruption is active you gain the following benefits.

• You gain invulnerability to necrotic, acid, and poison damage.
• You gain a swim, fly, and ground speed of 60.
• You may cast darkness and fear at will.
• You gain superior dark vision.
• You may use untapped prowess as often as you want.
• The ability check on Strength of the Corrupt is removed. 

Powers Unknown

At 15th level, the curse grows and you unlock certain powers that you did not know of before. As an action on your turn while Channel Corruption is active, you can now:

• You shoot two black spears from your hand. Make a ranged attack that deals 2d12+dex necrotic damage to one target or 1d12+dex to 2 targets, but you take 1d4 necrotic damage.
• You can use your lifeforce to strengthen your senses. Whenever you make an ability check within the next hour you may take 1d4 necrotic damage to add 1d6 to the total.
• You gain movement unlike any other being. You sprout wings made of a black energy. You can take 1d4 necrotic damage to gain a flight speed equal to your ground speed. 
• You gain the ability to teleport anywhere in sight, but must take 1d8 necrotic damage.

Dark Corruption

At 3rd level, either a relic you found or a deal you made put you in a struggle with a being that inhabits your body and over time it slowly consumes your soul, mind, and body. A mark or rune appears on your skin somewhere. You chose a god with a Chaotic Evil alignment and become connected to that god. You gain dark vision and advantage against being charmed.

Corrupted Companion

At 13th level, as you become more attuned to the god of your choice you gain the ability to summon a companion to fight with you. While Channel Corruption is active, you are able to summon a creature to fight with you based on that god's domain. Talk to the DM beforehand to determine what can be summoned based on your god. For example, if you are attuned to Talona, goddess of disease and poison you may be able to summon a snake, spider, or scorpion. This companion follows the same rules as the Find Familiar spell.

Ancient Endurance

At 17th level, the corruption has strengthened your body beyond any normal capacity. At the start of your turn while Channel Corruption is active and if you have less than half of your total hit points, you regain hit points equal to 1d10+consitution modifier.