What is the most feared lightsaber?

What is the most feared lightsaber in the galaxy, the one that strikes fear into the hearts of even the bravest Jedi and Sith Lords alike? Is it the iconic red blade wielded by Darth Vader, symbolizing his power and darkness? Or could it be the legendary purple blade, rumored to be wielded by ancient Jedi Masters of immense power and wisdom? Is there a lightsaber out there that surpasses even these, one that embodies pure terror and destruction? The galaxy is filled with whispers and rumors of such a weapon, but which one truly reigns supreme as the most feared lightsaber in the Star Wars universe?