Root

Root is a highly distorted anomaly lurking among the vast Omniverse with Contamination, whom he rescued from his deserted chunk of ground that was his entire Multiverse, to seek revenge against a certain unwanted visitor for destroying everything that both of them cared about. Before Root underwent this transformation into a barely comprehensible version of what he once was, he was actually one of the guards for Chief Asgore along with Undyne the captain of the chief's guards, and a lot of dog monsters.

Backstory
Underness, a Universe much like the original Undertale Universe, only much more primitive. Within Underness, there are no traces of technology anywhere, a quite noticable example would be the absence of the CORE entirely. Most structures are constructed of mainly mud bricks, tree branches from Snowdin, and leaves. Some monsters choose to rub leaves onto their homes and/or various structures to give it some color from their juices depending on what color the leaf is. Of course, much like how Undertale came to be, war had broken out which as a result, the humans had sealed the monsters underground with their ancient magic, forcing them to survive on what was inside of Mt. Ebbot rather than the fruits and wildlife that was among the surface. ((TBC))
 * Multiverse #000646052
 * Universe ID: "Underness"
 * Timeline: Pacifist

Absolute Perfect Accuracy
Root is able to land a perfect blow on his target with his crossbow every single time using his newfound corrupted eye. Trying to dodge this is rendered obsolete as Root is able to calculate the exact time and aiming to land his arrows on his target in what little time he has to land a blow on them.

Phantasmal Arrows
Thanks to his knowledge of taking down ghosts using specially crafted arrows from before his Multiverse suffered it's ultimate extinction, Root's arrows are able to take down spectral entities. The arrows are also capable of glitching any being medium-Metaversal and below out of existence entirely, anything higher up to high-Xenoversal can still be glitched out by these arrows, though they won't be able to glitch them out of existence unless they have been hit with several dozens, hundreds, thousands of arrows, depending on the target's overall power. Anything low-Hyperversal and above are completely unaffected by the glitch effect, though they can still be damaged by the arrows themselves. Not only that, but due to being corrupted beyond reason as a result of his Multiverse being destroyed, these arrows, should they in any circumstance miss and hit the ground, have the potential to completely glitch out the Metaverse that it landed in. Although it doesn't really do too much harm with just one missed arrow, the effects of it are permanent and should Root miss too many times, the entire Metaverse will completely glitch it's way out of existence.

Spectral Awareness
Root has had this ability since before his Multiverse was obliterated, it had only been hyper-enhanced after those events. Due to his magic/now corrupted eye, Root has always been able to detect spectral entities. After the destruction of his Multiverse, Root is now able to detect ghost-like entities at a much higher scale, even the much more difficult to detect spirits.

Teleportation/Hyperversal Travel
Root is able to teleport to all different kinds of Hyperverses throughout his Omniverse. He has been using this ability non-stop while carrying Contamination with him to try and find the perpetrator behind the destruction of their Multiverse for several years now, only time may tell if the two ever find the destroyer of their Multiverse...

Glitch Shockwave
By using his Teleportation ability in just the exact right order, Root is able to create a hypermassive shockwave of Multiversal proportions which will result in the Multiverse that it was created in to burst into thousands upon thousands of cosmic debris which will all drift out towards the nearest Multiverses to cause a mild glitching effect. Doing this in a glitched out Multiverse will cause the entire Metaverse that that Multiverse was in to crash, promptly erasing them from existence.

Corrupted Blood
As stated many times throughout this article, Root has become corrupted and glitched out to near-devastating proportions. Because of this, almost every part of him is now quite dangerous to even get near, even the blood leaking from his slash wound. Due to being corrupted from the destruction of his Multiverse, Root now bleeds indefinitely as if it were a fresh wound and does not feel any ailments due to losing such large amounts of blood, the effects of being corrupted are usually too powerful for him to feel anything else. As it turns out, Root can actually use his limitless bleeding to his advantage, normally by dipping his arrows into his wound before firing them at his targets, causing them to lose most of their motor skills upon hit. On a few rare instances, Root will straight up grab a glob of his own gore from his wound and chuck it at his targets, much like a fishing net. The effects of the blood have no effect on any high-Xenoversal beings and above.

Bone and Gaster Blaster Magic
Though Root has barely used them since the destruction of his Multiverse, he is still capable of using them. Although they aren't as powerful as his other abilities, he will still sometimes use them just for the fun of it.

Final Demise
Though his corruption has boosted his capabilities to unthinkable proportions, it has also left Root to be quite vulnerable to even the smallest tap. Should Root be exposed to any physical contact, his entire body will spontaneously combust into hundreds of chunks of severely corrupted code, all of the chunks combined would be enough to glitch an entire supermassive cluster of Universes out to the point of glitching out of existence should they all make collision with anything within the Multiverse that it's in. Although Root is fatally vulnerable to even the slightest physical touch, he makes up for that with nigh-instantaneous reflexes to dodge anything that might hurt him.

Trivia

 * Although some of Root's attacks can be devastating to multiple Multiverses and even a Metaverse, he feels that he doesn't really have any need to destroy any verses. All he really wants to do is exact his final revenge against the invader that wiped out his Multiverse.