I always thought the first wave of "heavier" vk and that inspired those as Origami, Golbeza, Re:dis etc. was around 2005-2006 with songs by Velvet Nightmare (later DI3SIRAE), Schmelz Cure, It, Since1889, 闇撫, THE RUDIE SATAN PARK, Leviathan and maybe even partly brodiaea or ネガ, followed by Silentline, GREGORY, GremlinS, UnsraW, THE CRIME, ヴェルテクス-Vertex-, etc. etc. etc. and the ones you mentioned plus maybe 20 other bands that disbaneded after 1 live distr. or even without any real CD.
But i think they dont have much in common and are not related to the likes of DIMLIM, Deviloof, etc. who more have influence from western and real "brutal" music?
Also i didnt feel JILUKA are brutal at all after seing them live with DIMLIM. Very much straight metal (but only "vk" band in 2017 i've seen where i felt the band knows how to really play their instruments) with some screams and kind/friendly/cute atmosphere live. But i dont know their discography at all (went for DIMLIM which were amazing despite the differences CD/live (damn the guitarist and bass cant play the stuff from CD live :\)), so maybe its me. Also FIXER are more like vk with electro effects for me and not brutal (at least not live; dont like them on CD, so maybe didnt listen enough). I think many bands these days have songs or part in songs that can seem brutal but i wouldnt call the band brutal. Some songs by Dir en grey are also brutal, no?
As mentioned by OP, I also actually think brutal kei was first used more in a way to make fun of certain bands as in writing it br00tal kei like many people hyping Leviathan in 2007 while others were disgusted by the hype. But i do think VkBrutaliaN was in fact the first person i've seen use it seriously some years ago