Unironically post-rock. Came out of math rock (which came from prog rock of course), which is by itself already an autistic rock genre and combines with post-rock, post-hardcore, extreme metal and metalcore to form mathcore.
Post-rock can be very emotional and energetic, and then very calm and slow, the intensity of the emotion portrayed in the sound shifting from somber melancholy to screaming, crying grief. Alternatively, from hopeful and tranquil to mood-elevating and elated. It's atmospheric and ambient, then hard and heavy.
It goes further in breaking rules than progressive or experimental rock put together, which it does, as well as other musical genres instead of just subgenres of rock. It has often a curious rhythm to it IMO.