Best thing is to download the video (loads to sites out there let you d/l YT as MP4 video) then go through it frame by frame, look for sprites and how they move/scale/fade. Your best process will probably be to use an in-engine particle FX editor, like in Unreal or Unity. They have lots of little tools for controlling…
The lighting makes the vegetation [if that's what it is] look like models and not vegetation... like I mean they look like they're made of steel or something and just plopped down there.
I really like that illustration of the elf cutting the dwarfs' beard. It looks like an old fantasy cover for a book which really cool. Like your style.