Show me your 'Mortal Enemies' / Rivals

This guy and Fyodor used to be friends, but their dynamic fell apart from a variety of causes (clashing personalities, unhealthy perceptions of each other, etc.). They were pretty toxic for each other since the start, but now it's at the point where they'd legit duke it out if they saw each other again. (Such a possibility is pretty likely considering that they're both pretty aggressive and petty... Not a nice combo tbh.)

He also dislikes his dad Jean-Paul, but to be fair it's more justified than his dynamic with Fyodor because Jean-Paul wasn't exactly the nicest fellow out there. (Still developing Jean-Paul's exact lore so that's why I'm being pretty vague here.)

Finally, Timothy is frenemies with his mafia superior Beverly. They bicker a lot and often exchange disparaging comments about each other, but they do genuinely appreciate each other to some degree + most of it seems to be in good humor. Timothy likes the attention Beverly gives him (even if it does get negative at times)., while Beverly finds Timothy to be a capable subordinate who even comes off as charming - albeit normally in the "haha you're so funny" way - at times.

Katla is frenemies with Ashta. If you see them you would think they hate each other but actually they are best friends and would have each others back blindly..but else they throw snarky comments at each others face and if Katla is fed up she just bites Ashta and paralyzes her scaly ass.

Toxic and Felix are rivals!!!

Both Toxic and Felix worked as private hitmen for the mob boss The Lady Of Ribbons. The two always fought over the best jobs. After awhile and learning about what Toxic's true self Felix grew to get a kind of obsession with Toxic, he enjoys being able to attack him any way he can, and Toxic never dying, he's made it a small goal for himself to try and find a way to kill him. The two have very different set of morals, while Toxic won't kill anyone he doesn't deem worthy of death, Felix will kill anyone he's able to, it's fun for him and he treats it like a game.

When Toxic finally left the mob Felix's hatred for him only grew. After hearing that he had teamed up with some Detective who wanted to take down the Mob, Felix got it in his head that if he can't kill Toxic himself, he might as well kill everyone who comes in contact with him. 

Misfortune and Chaos are enemies!!

Once brothers, the two grew apart over the years. While Chaos grew to love humanity, Misfortune grew to hate it even more. Chaos does love his brother, he just wishes that he could see there was more to life then what he's meant to do, he can tell theres some good in his brother, somewhere deep inside that mess of a body that just keeps to be getting worse with each year. Chaos can't help but remember a time where the two looked quite alike.

Virus and Ash could just fight each for the rest of eternity for all they care

Abigor and Scamp, two demons, mortal enemies.
Abigor is a high class demon very formal and pompous he only cares about his self-image and reputation and won't hesitate to kill to get to the top, he hates humans they're worthless and below him simply toys to play with.
Scamp is a low class demon, an utter brat of a demon just looking for mischief and mayhem he hates himself but hates Abigor way more, Scamp has complicated romantic feelings for a human and doesn't know what to do with them.

Baz and Leif are enemies!

Baz, an imp who is only focused and interested on the end goal of his construction, is not worried about the means he has to expand to get there

On the other hand, Leif is entirely focused on the preservation of the land he came from, and adheres to a strict set of codes and laws to dictate these issues.

So, you take an amoral demon who's actions are rife with consumption and put them against a spriggan, who's every action is based around edicts of preservation, and you have a problem.

They especially hate each other, mainly because they aren't an easy fight to pick. Both are pretty cunning and both have differing physical aspects that make every conflict they have an even battle.

Although not explicitly said, Brilliance and [Intellect] have some sort of rivalry going on. The reason as to why involves something of a betrayal of which is unknown.

A couple of other characters who are rivals are Red and Aven. Both of whom's lore has not been fully realized, so all I can confirm is that they are indeed rivals.

Rivalry is an interesting concept that I'd like to do more of in the future but for now these are the only confirmed ones.

Shin and Dai

I literally made these two to be rivals, but I still haven't bothered to draw them together 

But they just "hate" each other because they are opposites. Shin thinks Dai is a spoiled brat and that he talks too much, and he's right. Dai is just aggrevated by anyone who doesn't like him because he's been pampered and loved all of his life. The main reason they hate each other though is because they are in rival gangs and everything else just adds fuel to the fire. They are young, aggressive, and need to get some anger out. 

They have the type of dynamic where they are the rivals that are actually super interested in each other and would be "frenemies" in any other circumstance, but their bosses don't allow for any of the chumminess in the relationships between them.

Hadara and Aren for sure!

Hadara was raised, the daughter of a demon lord, to break the seals on an elder god's prison. It was her mission. It was the reason she was conceived. By time she was 18 and truly able to understand she was a pawn, despite the fancy words they used for her, she fled the fold. Demons found her time and time again, trying to drag her back, but they raised a warrior. She wasn't having it.

Enter Aren. Aren is a tiefling, much like Hadara, but of a less direct bloodline. She doesn't know her pedigree, nor does she really care. She wants to carve her legacy into the histories by herself. She found a weapon of sentience that offered her greater power and she took it. She didn't know about Hadara. She didn't know that weapon was supposed to be Hadara's as part of the ritual to release an ancient god. Aren and the knife, Shayd, began to work together, little things at first before the plan to free Tharizdun and his ilk became clear. Like Hadara, she's not so thrilled on the whole 'world ending' bit, but she's an opportunist. Who says when she cracks the seal she has to let Tharizdun free? She has Shayd. She has the Siphon. Aren's just going to try to take that power for herself.

Hadara's not so thrilled with that prospect either, however. Having recently learned of Aren and her involvement (minus the fact Aren is planning a betrayal, no one but Shayd knows that detail), Hadara has set out east to try and track her down. She refuses to see the seals broken by anyway, least of all a crazy bitch like Aren.

Zaruel and Remiel don't like each other at all. they really can't stand each other. for Zaruel, Remi is kind of shady in the way that he gets that Remiel is pretending or faking his good guy persona and that he never really exactly tells people what he's thinking and what he's feeling. for Remiel, he thinks that Zaruel shouldn't even exist because he's definitely not like an angel at all and that his methods are radical. that, and also he thinks that Zaruel never tells anyone what he's up to and what he's thinking. They argue a lot and even fight too, but they enjoy it.

Here's Marty!

Marty is Apollo's nemesis, who lost his sanity a long time ago. He was the hero in the shorts both he and his nemesis starred in. He basically became an insane murder, and wants to take his revenge on Apollo for stealing his popularity.