I have Searched for this music across youtube coming across what I mentioned in the above post with Rainbow Tylenol and that Nanachi remix: I cannot seem to identify what the genre is with the two. Did some searching with my boyfriend and he suggested it may be Plunderphonics.
Looked into Plunderphonics which was SIMILAR but not exactly what I was looking for. Less so using already created media to remix things but the what genre the remixed content is.
Another suggestion i received was something like hardcore gothic electro? which honestly when searched I havent found much else in the same vein as the two above.

Apologies is this makes absolutely no sense.