Rodolphus Lestrange and Ted Tonks
Ever since Ted Tonks and Rodolphus Lestrange had set eyes upon each other, they had instantly adopted a mutual loathing. Hate at first sight. Of course for Rodolphus, it had a lot to do with Ted's blood status. As the years went on though, they hated each other because of Ted's relationship with Andromeda Black. While Rodolphus hated that Ted was making a pureblood from a good family stray from what was expected, what most didn't know was that there had been a marriage contract set up between Rodolphus and Andromeda. Ted hated that he was taking Andromeda away from him and pulling her into his horrible world of murder and death eaters. However, it seemed that Ted won the first match after sneaking away with Andromeda on graduation night to elope. This made Ted another enemy, Bellatrix wasn't happy with Ted taking her sister or having to marry her sisters seconds. Later on when they were both well into their adulthood they had managed to survive many years with only the most minimal of contact, but then the war started up again. Rodolphus had a personal vendetta against Ted, and he was going to finish it off personally. There was no doubt in his mind that he would succeed as a death eater hunting down a wanted muggleborn. Just like there was no doubt in Ted's mind that he would die when he looked up from his hiding place and saw Rodolphus.
"I win," whispered Rodolphus in a malicious tone before raising his wand and shooting off the killing curse.