D&Dtools1

Inky black energy flows across your body, dripping to the ground and hissing with corruption everywhere it lands.
This spell adds a taint of evil to your magic, granting you special potency against your good-aligned enemies.
Your spells gain the evil descriptor.
Any spell you cast of 3rd level or lower deals +50% damage to good-aligned creatures.
As part of the casting of this spell, if you are a sorcerer you can sacrifice one sorcerer spell slot of 5th to 9th level; doing this increases the maximum level of spells affected by touch of the blackened soul to the level of the sacrificed slot minus 1.
For example, if you spend a 4th-level slot to cast the spell and a 5th-level spell slot to augment it, you would deal extra damage to good-aligned creatures with spells of 4th level or lower.
Special: An evil-aligned caster of the dragonblood subtype can choose to end this spell's duration by activating protection from good (as the spell, but targeting itself) as a swift action.
This effect lasts for the normal duration of protection from good.