Due to new ranking criteria rules, when the song is owned by a featured artist you don't need to add "osu!" In source. I recommend keeping that empty since recent Marenol maps (ranked) have empty sources
Explicit tag is refers primarily to the audio content of a beatmap, not applying to visual elements of a beatmap. The video contain gory, dismemberment, decapitation, and this is not appropriate.
So in this case, the video should be remove and explicit tag is no necessary, since the audio is fine
I did submit for content review, if u like disagree my point, u could wait for the result
If this is going for ranked then you probably should remove the background video as this is kinda too gory for osu's standards as the other ranked marenol's also don't seem to use this bg vid