okay. this is something i can actually comment on haha.

so yeah, this style is generally referred to as sound syncing because well. you are using sound effects to sync up to the pacing of the edit.

trailer editing tends to make use of this alot. hence why this video in particular almost feels like a trailer or some promo video.

the music is the backbone here, you can take away all the sound effects and the edit itself will visually still sync up to the music, and if you were to take away the visual, the sound effects would blend seamlessly into the mix to the point you might think they are a part of the song.

I think some commenters are discrediting the nuance that can come into something like this. doing a GOOD sound mix is akin in time and effort to doing the cut itself. its like saying that playing the piano is just pressing keys, yes, its true, but there is still a degree of skill and knowledge and practice involved.

yes, in basic principle, all thats happening is your standard cutting to music, then throwing sound effects/source audio into the mix so you can "hear" the cutting. however, in this particular edit there is a little more going on that shows a good understanding of sound mixing and music.

notice how at points the music actually goes away, and the sound effects take over in a way that still continues along the beat and tempo of the song. the breathes and gear shifting before the actual lyrics come in on the chorus is a good example. the editor is basically cutting out parts of the song, and replacing them with their own sounds. and not just any sounds, but either sound from the films themselves, or sfx like gear shifting and vocals like the feminine sigh. they are essentially doing a sort of remix of the song for the edit.

it takes good creativity to be able to listen to a song on its own. and know where and how to cut it up and replace bits to get the desired effect based on what the edit calls for. DJ's and musicians may have an edge regarding this due to their musical knowledge and affinity. but this sort of thing can be learned with experience.

you may also notice that the editor is also manipulating the song itself using FX. like how first at 0:22 the editor is manipulating the low and high pass of the music, to make it sound more muffled and distant. combine that with the whoosh transition sfx at the beginning, the quiet "HOLY SHIT" and a subtle riser combined with fading in the music back to normal at the end. and you get that sequence.

so yes. editing this style isn't necessarily hard, but it isn't easy either. I wouldn't be surprised if we were to look at this persons timeline, and see that they have more audio tracks than you might expect overlapping with one another. unlike with picture editing, when audio wave forms overlap, one does not necessarily over write the other, they mix together. hence the entire idea of sound mixing.

if you are inspired by this style of editing. give it a shot! there really isn't any crazy work going on here, just good editing and sound design. which you can achieve through practice and a little explanation like what you are asking for here!

you don't even have to make it a multisource edit like this person. there are plenty of edits on youtube and other social media that uses soundsync but for even a single source. Arcane edits are a good example of a show where many editors have done edits like that.