"Have you ever seen true carnage, Ser?"
The mans eyes were wide with madness, their whites disturbingly offset by thick layers of blood and viscera that coated his face,
"I... stood at the back. We should have never gone in. But the stories... the cults of the dragons are so easily cut down by the Founders..."
He swallows - a mistake - as the bandage around his neck bubbles,
"She cut us down... she barely moved... In a second, the air was full of limbs, heads, eyes... I...."
His eyes are now overtaken by horror, pupils dilating, shaking rapidly. And then, they are still. Eyelids are closed. A mercy. 

Forged in dragonfire by the scattered remnants of the Chromatic Church, the whip-blades of the cults are typically wielded by their enforcers to great effect. Guardsmen whisper of what is found in the wake of a cult attack, and the stories are all strikingly similar: "No Survivors. They're still piecing the bodies together." You have a +2 bonus to attack and damage rolls made with this magic weapon. When not in its Unleashed form, this razor-sharp whip looks like a bladed whip, and does an additional 1d6 slashing damage.

Unleashed. Upon using your action to Unleash Wyrmrazor, you speak a command word of your choice upon attunement, and let the whip fly into a storm of carnage, creating a 15-foot cone of whirling blades. Each creature in that area must make a DC 16 Dexterity saving throw, taking 6d6 slashing damage on a failed save, or half as much damage on a successful one. In addition, any creature caught within the cone at the start of their turn must treat the area within the cone as Difficult Terrain. You may use this feature three times, all usages resetting on a long rest.

Proficiency with a Whip allows you to add your proficiency bonus to the attack roll for any attack you make with it.

Notes: Bonus: Magic, Damage: Slashing, Damage, Combat, Finesse, Reach, Slow