High Blood Pressure

There seems to be excessive pressure of blood or liquid constantly flowing through you in combat. When its drawn it causes you to unleash both your blood and bloodline.

Increase your constitution by 1.

When you take slashing or piercing damage, you can use your reaction to have your blood burst out your wound onto your adversaries. Anyone in a 5 foot cone in the direction of the attack must make a constitution saving throw against your constitution score or be blinded for a turn. This ability refreshes when you are healed to full. Depending on how you got this feat, this does even more to your enemies.

Dragonborn, Genasi and Draconic Subclasses: Deal 1d10 plus your constitution modifier elemental damage depending on your heritage

Barbarian: Deal 1d6 psychic damage plus your constitution modifier and disadvantage on the next charisma, wisdom, or intelligence saving throw

Plasmoid: Partially assimilate them, causing them to have to make a charisma saving throw against your constitution or be charmed by you. Additionally, if they die while charmed you can control their body for an additional turn.

Wild Magic Background or Subclass: You have a wild magic surge

Halfling: You give them a d4 penalty to checks and rolls (bane) for 2 turns

Aasimar or Celestial Warlock: You activate your class feature Celestial Revelation without expending your tokens for the day, but only for the amount of turns as your constitution modifier

Tiefling or Fiend Warlock: You deal 1d6 fire damage plus your constitution modifier and leave lingering fiery terrain until your next turn in that cone. 

Undead, Necromancer or Circle of Spores: You deal 1d10 necrotic damage plus your constitution modifier and decrease movement by 20 feet.

Circle of Spores, Green Dragonborn and Drow: Force a constitution saving throw against your constitution to inflict poison for 2 turns