The Empire Shall Fall is normally categorized on the Internet and other places as a metalcore band, and they may indeed be a metalcore band (I don't know, as this EP constitutes my first encounter with this band) but, apart from a couple of metalcore breakdowns in 'Narrow, The Path I walk Part II' and the occasional use of typical metalcore screams, the dominant feature on this album is the djent sound.
So rather than djent-infused metalcore, I'd say that this is metalcore-infused djent (if you believe in djent as a genre), and it has all the elements that make djent progressive, such as the mind-boggling rhythmic patterns (well, compared to much other djent-based music, the grooves on this release are "only" mildly mind-boggling) and the technically advanced playing, but there is more progressivity to this release than just the djent-elements.
For example, a track like 'Narrow, The Path I Walk II' contains a middle section with references to psychedelic 70s rock, including organs and bluesy guitar-solos with 'oohs' and 'whoahs' on top, while 'As The City Sleeps' features a semi-jazzy passage and also some smooth midnight saxophone. The kinda epic 7-minutes 'The Martyr's Song' has more of a sludgy groove to it and features twin guitars as well as mellow intermezzos every now and then, and its overall drive is reminiscent to that of many The Damned Things tracks.
While metalcorish at times, the vocals also feature many clean passages, often sung in a way that might be associated with sludge metal and alternative metal. The musicianship is top notch, and the music is definitely complex - yet it is kept accessible enough that most listeners should be able to follow it. Oh, and the album is jam packed with tasty guitar licks.
Volume I: Solar Plexus is the first installment in a series of EPs, and if this fine work of djent metal is any indicator of what the rest of the EPs will sound like, then I am definitely going to check them out, too.
1. The Genesis Of These Scars
3. Narrow, The Path I Walk Part I
4. Narrow, The Path I Walk Part II
5. As The City Sleeps
6. The Martyr's Song
7. The First Redemption