Crimson. There are not many ways to describe him. One might say that "evil" would suffice. Well, let us tell you: "evil" does not even begin to scratch the surface of the horrible, demented, malicious, psychotic mind that is Crimson. It is almost impossible to describe in regular terms how unbelievably evil Crimson is. He has no heart. He has no soul. Crimson will not hesitate to brutally kill anyone who gets in his way, and he enjoys it, too. He is the living, breathing incarnation of hatred and wrath. This, everyone, without question, is the most evil being to ever live.
NaN and Crimson seem to have a history in most omniverses. In most of these, NaN is the omnipotent goddess with absolute power over absolutely everything, and likewise Crimson is the ultimate evil. And again, in most of these, NaN is born first. She was well aware that Crimson would be a huge threat were he to come into existence, and so NaN kills off Crimson immediately before he can grow stronger, and doesn't tell anyone about it.
However, the Crimsonverse was different. This time around, Crimson was born first. Being the evil douche that he is, he killed NaN while she was still a weaker larva. Until she respawned. So Crimson killed her again and again, getting more aggravated each time... until one time, she didn't respawn. Crimson, absorbing NaN's glitch powers (which were still weak, so he didn't get much) had established absolute power in his own omniverse.
Crimson is brutal. He is the sole ruler of his own omniverse, the Crimsonverse. Everyone that lives in this omniverse fears Crimson. He does unspeakable crimes to his residents. He regularly tortures the survivors, making everyone's life a living hell. Just about the only reason Crimson lets anyone in his omniverse live is just to have more unfortunate victims. Even the land ITSELF has become bloodied, something out of your worst nightmares. Horrifying creatures of Crimson's creation prowl about, hungering for blood to return to their master. It's a dark place, and you should never go unless you're insane, suicidal, or were paid to do it.
Any who oppose Crimson end up murdered so violently we're not allowed to go into detail here. Although he by no means relies on it, he feeds off fear, too, and can exploit it so well he has taken down opponents nearly as powerful as him effortlessly. Crimson's body isn't actually a solid material, so he has several main forms as well as millions of "minor forms" that would take very long to describe, so we won't.
Crimson even has the unique trick of entering someone's conscious and KILLING THEM FROM WITHIN. He is usually even more powerful in other people's minds as he can alter reality to his whim in there, but unfortunately for him (and luckily for us) he doesn't get to keep those powers once he's claimed his victim.
As for his personality... do we need to even say anything? This is the guy who enjoys killing his enemies by methods such as slowly decapitating them and putting through his custom-made meat grinder, and even worse than that. The guy who spreads nothing but negativity (and probably death) wherever he goes. The guy who has taken down gods and absorbed them by exploiting every one of their weaknesses.
As you can see, this guy is pretty evil.
Association with the Four Bringers
Crimson, as evil as he is, even he got bored of doing the same thing all day, every day. He started looking beyond the Crimsonverse, having new, bigger goals... he planned to conquer the entire UnHyperverse. As arrogant as he was, however, Crimson was careful, too. He knew doing this alone was impossible. As a result, he looked to the other omniverses, and gathered three evil, bloodthirsty, beings to take over whole multiverses, after which Crimson annexes into the Crimsonverse. Thus, the Four Bringers of the Apocalypse were founded, and they've been very successful so far.
- There used to be a Crimson in our UnOmniverse, too. Luckily, NaN came before him and swiftly killed this Crimson before he could do any damage.
- There are rumors that Crimson plans to betray the other three Bringers once they've achieved their goal. Knowing Crimson, that rumor is most likely true.