Inkweaver Sorcery

When those who say art imitates life gaze upon an Inkweaver, they understand it is life that imitates art. These sorcerers are connected to ink and paints as though it were their lifeblood. In some extreme cases, it actually is their lifeblood, with rumors and stories going around of magical children who touched paintings only to find themselves become part of them or have their body change to reflect the artstyle. Thus, their power is drawn into existence through sheer force of will and pigment. What begins as a stroke of the brush becomes something real, as their creations slip free of the page and into the world, sustained by their artistic vision.

Level 3: Magical Inks

You gain Proficiency in Painter's Supplies and can make checks that utilize them using Charisma. Additionally, whenever you expend one or more Sorcery Points, you leave behind magical Ink Spots for each Sorcery Point expended. An Ink Spot has a 5-foot radius, can appear at any point on the ground within 5 feet of you, counts as Difficult Terrain for creatures other than yourself, and lasts for 1 minute or until it is consumed.
As a Bonus Action, you can consume any number of Inkspots within 30 feet of you to gain Temporary Hit Points equal to your Charisma modifier times the number of Ink Spots consumed.

Level 3: Play in the Paint

Whenever you cast a spell of Level 1 or higher with an Area Of Effect, you can increase one dimension of the spell's area of effect for this casting by 10 feet per Ink Spot within 30 feet of you, consuming it.
For example, if a spell creates a 20-foot-radius Sphere, cast consuming 2 Inkspots would increase the radius to 40 feet. A spell that creates a Line that is 5 feet wide and 300 feet long, cast consuming 1 Inkspot could make a Line that is either 15 feet wide or 310 feet long.

Level 6: Blot Out

As a Reaction to being hit by a Spell Attack or failing a saving throw against a spell, you can create a shield of ink to diffuse the blow. You gain a bonus to your AC against that attack or a bonus to that saving throw equal to your Charisma modifier (minimum of 1). If this bonus would turn a hit into a miss or a fail into a success, you create a number of Inkspots equal to your Proficiency Bonus.
Once you use this feature, you can't use it again until you finish a Short or Long Rest, or until you expend 3 Sorcery Points to recharge it (no action required).

Level 14: Painted Landscape

Whenever you consume an Inkspot as part of casting a spell, if the spell has a duration of 1 minute or longer, you can choose to add one of the following effects instead of increasing the spell's area:

Black & White. Each creature of your choice in the area has Resistance to Acid, Cold, Fire and Lightning damage.

Cubism. Each creature of your choice that starts its turn in the area must make a Dexterity saving throw against your spell save DC. On a failed save, it has the Restrained condition until the end of its next turn. On a successful save, its Speed is halved until the end of its next turn.

Vibrance. Each creature of your choice in the area has Advantage on Charisma checks and saving throws.

A spell can't benefit from more than one of these effects.

Level 18: Inkmaster

Your Blot Out feature now works against all attacks and saving throws, not only those originating from spells, and you can regain a use of it by expending 2 Sorcery Points instead of 3.

In addition, you can apply any number of Painted Landscape effects to a single spell.