In a dimly-lit, coffin-shaped venue during the depths of last December's winter chill, deservedly-hyped Swiss duo Bölzer made their headlining debut on Ireland soil. As the venue's lights lowered, guitarist/vocalist KzR and drummer HzR – both of whom resemble characters from Mad Max – arrived onstage in front of approximately 150 eager onlookers (this hack included).

What followed was enough to elevate each audience member to another astral plane: the duo's instinctive interplay brought the otherworldly music of Aura – their acclaimed 2013 EP for Invictus Productions/Iron Bonehead – to life. HzR's massive arms swung drumsticks that seemed like wooden weaponry in motion; the sheer strength of his drumming and his shrewdly orchestrated approach to filling space with each emphatic beat proved to be the perfect foil for KzR's shamanistic guitar histrionics. The demonic blackened death metal riffs and bizarre (dis)harmonies KzR wrenched from his guitar reverberated around the room as if transmitted from another realm. His extra-terrestrial B.C. Rich guitar a conduit; his echoing screams a portentous punctuation mark. It was a show which made music that, on record, sounds not-of-this-world, appear to be almost human in the flesh, because you could see the mechanics behind it. In saying that however, a piercing feeling that what was witnessed that night belonged to something more subversive than our mundane existence remained.

There are few extreme metal bands outside of Bölzer who can currently create such an evil atmosphere on wax and heighten the feeling of being flung face-first into the fiery abyss in a live setting. It is this rare ability – reminiscent of prime Morbid Angel – which has made Bölzer one of the most exciting underground metal bands to come along in an age. Their selective live shows – like the one romantically detailed above, or their debut appearance at this year's Maryland Deathfest (at which Bölzer ended up playing two sets) – have begun to take on a legend of their own and, in turn, have cemented the band's reputation prior to the August release of the successor to Aura – a second EP titled Soma.

Bölzer have clearly kept their mind-altering live show centred like a third-eye when creating the two tracks that feature on Soma: 'Steppes' and 'Labyrinthian Graves'. Both songs are structured to shatter whatever venue Bölzer are conjured to. 'Steppes' (which has been available through Soundcloud since April) combines into one song the same entrancing Blut Aus Nordian discordance that made Aura's three tracks so thrilling – and like 'Entranced By The Wolfshook' before it, 'Steppes' will no doubt become a Bölzer anti-anthem. Taut in its bearing and becoming more martial as it progresses  – with HzR rolling through a number of fierce snare and tom fills as the fragmental riffs align – 'Steppes' sacrifices the intangible strangeness of '…Wolfshook' for an impressive display of immovable structures and brute force musicianship, heavy on syncopated death metal groove. Vocally, 'Steppes' lacks the anguished cries KzR favoured on Aura and the band's crucial 2010 demo Roman Acupuncture. But because the song's intention is to harness complete power, KzR's array of shrieks, severe growls, spoken-words, and even throat-singing supplement the more straight-forward purpose behind this song, while at once whipping up a torrent of theatrics.  

Remarkably, where 'Steppes' reinforces Bölzer's sound, 'Labyrinthian Graves' displays an eagerness to expand upon it, giving the listener a probable glimpse into what may come from the highly anticipated full-length debut the duo has been threatening to deliver over the last two years. Sporadic fills and intermittent double kicks begin 'Labyrinthian Graves'; the riffs hiss menacingly in the background. Blasts purge and the song rushes forth; it's war-like and remains calculatedly so. The oddly-phrased riffs creep in with the drums locking into a churning groove, and the music continues to contract and explosively expand, over which KzR's vocals – similar in feel and layered delivery as those found during 'Steppes' – create the desired disorientating effect. Such dynamism within one song is what makes Bölzer so striking. The way in which the band bludgeon brutally and then return to the shadows with ease of transition is something that takes time to master. Yet even though the band has only released a handful of songs at this point in time, we've now come to expect this kind of instantaneous tension and release mastery from Bölzer. That's why the Burzumic ending of 'Labyrinthian Graves' comes as a surprise, and it really finishes Soma on an intriguing note; its austerity is based on simple repetition and eerie atmospheric, recalling Hvis Lyset Tar Oss, which leaves the listener aching in anticipation for what comes next from this band.

Whether intentional or not, Bölzer's astute "leave the listener begging for more" approach to the releasing their music thus far has played a major part in building the hype around this Swiss duo. However, some doubt has been cast as to whether the band can deliver when it comes to writing music for a full-length album. Quite frankly, such suspicions are absurd, because the quality of Soma – which actually works like a side B to Aura's side A (even the artwork of both releases share similar images) – in tandem with the two preceding releases, marks Bölzer as a band whose journey is only beginning, with the end destination potentially endless and entirely in this duo's wretched hands.