Corrupted Soul

Across a field of green grass and beautiful trees sits a pile of rubble, just outside the pile of rubble is a figure with crooked fingers and darkened hands, their hands glowing with disgusting energy. The figure raises their hand, and the trees begin to be sapped of life, the grass turns to ash. This is the power of the Corrupted Soul Sorcerer.

Corrupted Sight

Your eyes cast light through the darkness around you, but it's never the same.
Beginning at 1st level, you gain darkvision out to a range of 60 feet. If you already have darkvision, it extends out another 60 feet. This darkvision is off, while it allows you to see in the darkness, things are warped.
You can also see through magical darkness out to a range of 60 feet.

Corrupted Spell Casting

Starting at 1st level your corruption allows you to add harm to your spells.
When you cast a spell of 1st level or higher that deals damage, you may use a number of sorcery points to add that much necrotic damage to the damage roll.

Foul Mark

Starting at 6th level, your soul becomes a vile form of its former self, spreading its influence throughout your body and your magic.
Upon casting a spell on a creature that requires a saving throw, if the creature fails the saving throw, you may mark it with your corruption. For 1-minute the creature is frightened by you and allies can add 1d4 to their attack rolls against this creature.

Corruptable Minds

Beginning at 14th level, you can place a drop of corruption within a creature.
As a reaction to being attacked you can cause a creature to make a saving throw against your spell DC. On a failure, the creature will lose its attack. On its following turns, if it attempts to attack any creatures it will need to repeat the saving throw, if it succeeds it no longer needs to make saving throws.

Forsaken Visage

At 18th level, your corruption takes a physical form. As an action you may cast out your Forsaken Visage, all creatures (including the caster) within 30 feet of you must make a saving throw against your spell save DC. If a creature fails this saving throw, it becomes petrified for 1 minute as its soul becomes corrupted. Creatures may remake the saving throw at the end of their turns.