What champ(s) should I buy? [not short question]

I don't know which champs should I buy I got a decent couple of them but I feel like I miss someone yet I feel like no champ I buy is going to fix that..... Champs I own are mostly Assasins, Carries and similar to this type of thing. I'm aiming for champs that are not same stuff same combo over and over again but really the ones because for example sounds like a one directional champ but there is lot of choices to Q in/walk up save Q/when use W, when use E, etc. u get me?

I was thinking about since I am irritated by people constantly picking meta and overtuned bull all the time in games, I got enough to buy Sett but I don't like buying new champions too early even if they cost 6300, I mostly play Mid, Jg but I can pretty much play every role besides support which I can play really good like but just don't prefer it in ranked because I need to rely on adc that sometimes isn't optimal and I don't get autofilled too much.... I was also thinking about but playing adc mid gives some disadvantages in your cards or team overall. I thought about but I don't know how strong he is because almost nobody played him last time I seen wukong was like more than 3 months? and sounds good. I'm aiming for a midlane champion(s). I had a thought about since I'm not trash.. I thought about playing AP mid since I tryed it in free rotation and it turned out really well I could play optimaly against fed enemy carries and help win. I got 10 000 BE. Champs I already have A-Z:

I enjoy playing sometimes I don't mind playing I smash people with him mostly.

I appreciate every single thought out answer that could short my brainstorm. (doesn't have to be long thought ;) )

[slayer-pantheon-thumbs] Thank you.