Nesseria play chaotic, ripping hardcore with some tech-y guitar parts. You can see them citing Botch and Converge as influences. Luckily for Nesseria, they don't fall deep into the 'wankery lead guitar part' territory that ruins Converge, definitely recommended to fans of those two. It also adds blastbeats, but that alone doesn't really make it "grind". The Converge part is very true though, the vocalist seems to have listened a lot to Jacob Bannon and the music is very similar, be it without the melancholic songs Converge has on each album. "Choatic hardcore with blastbeats and metal parts" would make a perfect description. It's well executed, with a good production, fitting the music quite well.