I think Liam Neason's character Bryan in Taken said it best when it comes to going after someone. "I will look for you, I will find you, and I will kill you". Beyond the fact that the line was delivered perfectly, Bryan certainly lived up to that promise. There are comic book characters who are just as if not more persistent and ruthless when it comes to revenge or taking someone out. Characters who's bad side you do NOT want to be on.
Of all the characters in all of the Marvel Universes you don't want after you, I vote Victor Creed number one. First off, Sabretooth is just vicious and flat out physically intimidating. Six foot six inches, built like a truck, moves as quickly as his animal's namesake, and has teeth and claws that he loves to use on people. What makes things even worse is that you'll never escape him. Because of Sabretooth's heightened senses you'll never escape him. So once he has your scent, you'll never be able to get away from him. He's got your scent for life.
We all know about his rivalry with Wolverine and how they've spent a good part of their lives taking chunks out of each other during fights. What makes Sabretooth so devious is that he makes things as personal as possible and he won't stop at doing it just once. Sabretooth pledged to try and kill every woman that Wolverine ever cared about and he's made good on that promise over and over again. And if Sabretooth doesn't kill someone Wolverine loves, he will do something that will ruin Wolverine's life on some level. Like showing up on Wolverine's brithday and trying to kill him.
In order to make an omelet you have to break some eggs. Nick Fury is not only willing to break some eggs, Nick Fury is willing to break as many eggs as possible to get the job done. Fury lives in a world where he feels he is the only person that can get a job done. Therefor, there is no limit to how far he will take a grudge. People are certainly going to die, but as long as the world keeps on spinning, Nick Fury knows he has completed his job.
It's Nick Fury's patience that makes him so dangerous. Going in recklessly is almost never the smart thing to do, so Fury bides his time and waits for the perfect time to strike. When S.H.I.E.L.D. was compromised by Hydra, Fury used this information to his advantage. The whole time Baron Strucker thought Nick Fury was secretly working for him, Strucker was actually Fury's pawn the whole time. And when the time was right and Strucker outlived his usefulness, Fury killed him. Not only will Nick Fury use a person up, but once he's done with them, he will kill them right after.
With Mystique, it's not so much the physical pain. It's about the mental scars she's going to leave after she's done with you. That's not to say that she isn't versed in beating people down because she certainly is. But that isn't Mystique's style. When she comes after you, she is trying to beat you down in such a way that it will turn your life and the way you live it upside down forever. Mystique's shape-shifting powers topped with her uncanny ability to find people's weaknesses and her willingness to go the extra mile to get in someone's head usually lets her get what she wants; whether it's fortune, revenge, or because she's bored.
Mystique's willingness to go the extra mile makes her even more unpredictable than most people. Prime example is her having sex with Wolverine who killed her a few weeks prior so she could have it recorded and sent to his girlfriend. Yes, Mystique did that. She is completely okay with having sex with a man she hates to get revenge. There's only one other person I can think of in Marvel that willing to go that far and he's up next.
The son of Wolverine. He may not have all of his father's skill or his strength, but Daken makes up for with a few things his dad doesn't have. Wolverine has gone away from manipulating people to get what he wants while Daken prides himself in doing that. It helps that Daken has pheromone control that allows him to make people feel however he wants them to feel. He's used this power to get money, power, and tons of sex. Daken, like Mystique, would much rather avoid a physical confrontation. But, unlike Mystique, Daken enjoys dismembering people and dancing in their blood. Daken is all about power and letting people know that he has it and that he is superior.
Daken hates his father. No matter how many examples are given that Wolverine isn't responsible for Daken being raised by a monster that turned him into one. When someone has that much hate inside of them they will do anything to destroy the representation of that. So what does Daken do? He puts a group together that's only criteria to join is that you want Wolverine dead. This group put together a plan that sent Wolverine to Hell (literally) and also set Wolverine up to kill kids he didn't know he had and Daken had no remorse when the plan was completed.
What you saw in the Daredevil Netflix show is nothing compared to what the comic book Punisher is capable of. You can't bribe him, threaten him, or persuade him. If The Punisher wants you dead then you'll have to kill him in order to stop him. Unlike the other people on this list, Frank Castle has no powers or added extra anything keeping him alive (Nick Fury has the Infinity Formula Formula in his body). So when Punisher's going after someone or something, he's only using guns and other military kind of ordinance. It's the planning that makes him so dangerous. He finds out everything about you and then uses it against you. If you are in his sights, you never get out of them.
The best example of the Punisher's persistence is when he went after the people who caused the death of his family. I'm not talking about the shooters. I'm talking about the guys who were responsible for the shooting. It's one thing to hunt them around the country, it's another when you chase them down in prison. Punisher got himself arrested and took multiple beatings from cops and inmates all to make sure the people responsible for his family's death died. THAT takes dedication. Do you want a guy that's willing to go to jail and take a beating daily coming after you? NOOOOOOPE!!
You're probably thinking "Well what about...", but don't worry. This is only part one. Tell me who you think is the deadliest of this group or if you think I missed the mark all together. Stay tuned for part two coming next week.