
At the end of chapter 3, I get that he just woke up and was still half asleep when he was kissed but how could it be they made out the whole night and he woke up not remembering. He wasn‘t even drunk, that behavior just seems so weird to me and it‘s not explained at all. Like how could he not know what he was doing?!

On ch.1 pg.5 there are a lot of manga shown and there is one without a name.. on the cover you can read something with ˋmagic powerˋ but I think thats not the name.
Can somebody please tell me the name if you know?! ٩(๑❛ᴗ❛๑)۶

I think you're talking about this one http://www.mangago.zone/read-manga/chihira_kun_wa_maryoku_ga_tarinai/

A pairing with three people could be interesting. I‘d like to read a story with three people pairing up and all the consequences and conflicts. This story here ended just when finally the interesting plot was about to start

This story actually features a pairing with three people and there's a sequel as well.
http://www.mangago.zone/read-manga/there_s_no_way_this_is_fate/
I don’t really get why the blond guy went insane so fast ╮( ̄▽ ̄)╭
Also I really wanted an explanation for why the black haired one lost his abilities and the other got to keep him. Also wasn‘t the only reason he liked him because he couldn‘t hear his thoughts?
I think he didn't go insane so quickly. I mean in the 5th chapter kinda showed that someone killed the students who were bullying Katou on the news report. The students were still 17, so that meant that someone killed them when they were still in school. And when Oda said that Katou was special regardless of having powers, I think that just means he was always crazy.
Just that the whole hearing thoughts thing made him more insane because it "confirmed" that Katou was his or smt ╮( ̄▽ ̄)╭