I know what you're thinking, people have discussed dark guardians before and Dredgen Yor along with the Cult of Yor have existed as well. I have a couple ideas on how a new Guardian antagonist could be introduced or make an appearance. I also had some insperation from Broly, a well known villan in DBZ. That's where this dark guardian gets some of his traits. (Also this won't be extremely detailed, and it's a bit long so there's a tldr at the bottom) My main idea starts with a Titan who had a troubled past. He was out with a fireteam exploring a hive area (whatever it could be called, on some planet that has Hive on it, could be anywhere really). They were ambushed, they split up and in all the commotion and gunfire one guardian got split apart from his fire team and ghost. He ran wounded only going deeper and deeper into a hive fortress, shooting the last of his ammo and tossing away his weapons. He got shot in the leg and tell to the ground and couldn't walk. Thinking it was the end he just layed still waiting for a killing blow and it never came. Instead wizards surrounded him, chanting, talking to him. They knew he was separated. They used this to their advantage and imprisoned him. He was stripped of his armor and tortured, experimented upon, convinced he was left for dead by his fireteam. Dark energy corrupted him and he began to hate the light, guardians and people he once fought for. His body mutadted, becoming pale, his skin looking like an ogre's, he grew to about 8 feet tall but kept the body structure of a human. His strength increased greatly, to the point where the ground would crack under his feet. After so long he was released from his cell, but chose to stay with the hive. They spared him, and now they shared a common enemy. His powers, corrupted by darkness, were extremely powerful and different. Knights forged him armor made out of bones and chitin of those who had fallen there before. Wizards had found weapons of those unfortunate people as well and corrupted them as well turning them into weapons of sorrow. He then left, the Hive had no worries letting their abomination loose to wreak havoc on the light. On the planet he was on he enountered a couple of guardians, a Warlock and Titan. When they saw him they didn't shoot, they tried to ask him questions, and if he was okay but he didn't respond. He only walked towards the two. Once within 15ft or so of the Titan he lunged forward almost teleporting to him and held him up by the neck, lifting him off the ground and crushing his throat. The Warlock whipped out a hand cannon and fired a whole clip into him before he turned his head to the Warlock completely unphased. He dropped the Titan and quickly went to the Warlock throwing a lunch at he lower abdomen that ripped through her body and out her back. Their ghosts were stunned in fear. Before they could contact the Vanguard or resurrect their guardians he crushes them with ease. From their he found their ships, took one and began to head from planet to planet killing guardians, people and other alien species with ease, and helping the Hive spread. TL;DR [spoiler]Male Titan unintentionally left for dead by fire team and ghost in a Hive fortess lead to him being captured, corrupted and mutated. He became one with the darkness basically and so did his powers. Then with armor made out of bones and chitin, darker powers, powerful abilities, increased strength and corrupted weapons he went out to destroy anything the light had to offer decimating a couple guardians pretty quickly and taking their ships to bring his rampage elsewhere. [/spoiler] Whatcha guys think? If you have any questions feel free to ask.