How do I get better at Magik

Been playing this game for a bit. Ive recently been trying to get good at magik, but I cannot make them work for me. I spent time learning the combos, and spend time practicing them in practice mode, I have a general idea that you are supposed to flank and go after the healers as magik, I went and found video guides and stuff. But it feels like every time I try to do something, a dps comes in and melts my puny health bar, or the other healer allows the target of the oneshot combo to survive, and I just dont get what im doing wrong.

Is there anything I could be doing wrong? I really want to get good with magik but I cant make it work. I dont think im bad at this game. I consider myself pretty good at characters like loki, storm, strange, and winter soldier. But I just cant figure out magik

I dont really play that much ranked, and mostly stick to quickplay. Thank you for any advice you can give me. Have a nice day/night