Perhaps Periphery's (and progressive metal's) most pristine work. It could be argued that Alpha / Omega is an evolution, but this is the gold standard foundation to support everything after that fans of the band will look back at 20 years later and say "that was it". Ragnarok has one of the best climaxes in metal music period. If you've never heard this album and you like metal music, buy it. Listen to it 5 times. It is one of those gems that you may not comprehend initially, but it grows on you, it molds you into it and it stays with you, like any leegendary album should.