There’s a lot of entities that can contribute to this.
Andras isn’t as much a killer as much he causes chaos and disaster, but there’s a strong chance he will also bring some of that to you, even if you ask him not to… it’s his thing. He’s fine if you don’t mind weathering some very shitty luck, like, minor car accidents type of bad luck. If there’s a chance you could be in the car when it crashes, or the house when it’s burning, don’t ask Andras. I didn’t listen to this advice before, and despite precautions still experienced this first hand. I love Andras but he’s a wild card.
Since you said ‘destroy’, by synchronicity Abaddon the Destroyer might be interested.
Michael is excellent at punishing the judged, though he will teach you to kill them
Glasya Labolas is popular for asking for people’s death.
Dra’talon kills very slowly by causing madness
Gods involved with chaos and death from any pantheon might be interested, but I feel usually want more of a relationship at the same time. That’s includes people like Loki, Hel, Hekate, The Morrigan, Kali, Santa Muerte… So for a one off I’d say stick with Daemons that like doing what they do for the sake of doing it.
Having said all that, there’s a lot to be said for walking away if not just cutting them out of your life. For one, this by itself hurts some people, and for another, it frees your energy to work on something that directly benefits you. It’s going to cost a lot of emotional an physical energy and time to perform the rituals and very often you need to repeat them to get the energy to stick. That’s a lot of hours you could have spent bringing fortune and opportunity to build your personal kingdom where shitty people can’t touch you, gone down the drain, imo. Because seeing them have some bad luck that you tend to doubt you caused anyway isn’t all that satisfying.