When one makes references to past Metal genres, one thing must be clear: you must make the right references, because to say Old School something doesn't mean a thing at all, unless you point to a specific form of music. As an example, what's Old School Black Metal? The set of answer has no end, so a better set of ideas must be put under the table. The Greek one man band SULFERON is an Old School Black Metal band, as "Calesti Irrumator" shows, but what it means, in the end of all?

First: on the album, some influences of what is defined as Hellenic Black Metal (founded by names as ROTTING CHRIST, NECROMANTIA and VARATHRON) and something from MAYHEM and DARKTHRONE as well, can be detected on some moments, but what's heard is influenced heavily by Swedish Black Metal School, especially MARDUK (it's not a mere coincidence to hear a version for "Throne of Rats" on the album) during the days between "Opus Nocturne" and "Plague Angel". But the band's has its own personality, so don't expect constant fast tempos or only the half speed of the old days. It's not so simple, but's full of energy and good musical ideas. The production isn't as good as it could be. It's obvious that the old roughness of the past has a crush on the band's music, so the idea of using a crude sonority came along. But the tunes could be better set, because the tunes of the guitars and drums aren't fitting perfectly on what is expressed on the songs. It's not bad, but could be much better.

The massive and brutal approach of "God's Absolute Right" (fast and thunderous, with extreme tempos on the rhythmic session sustaining the growls and shrieks of the vocals) and on "Christcunt", the contrasts shown on the band's version for "Throne of Rats", the good ideas for riffs used on the climatic and morbid "Mouths Like Open Graves" (these tunes used for guitars really could be better, and not on this way like frying potatoes), and "Blessed by Satan Himself" are the best ones for having the right idea of what the band has to offer. It's not something new or a revolution in Black Metal, but's truly what some Black Metal fans are looking for.

The value shown on "Calesti Irrumator" isn't torn apart due its sound quality, but Typhonas (the mastermind behind SULFERON) must find a better way. The songs are really good, but a better production would make miracles to the band's musical work.