An accurate translation for those who wanna know: Darker than darkness, deeper than the abyss. (That is) the shadow cast by the light of science! Japanese original: Yami yori kuroki, shinen yori ideshi. Sou da, kagaku no hikari otosu kage. TL notes: One of the most common translations is "Darker than darkness, emerging from the abyss... The shadow cast by the light of science...". Which is good, but more focused on the feeling and meaning of the whole than the actual meaning of the individual words. For example it never says "emerging" (the light) anywhere in the sentences. Instead: It is said that A (darker than darkness, deeper than the abyss) is in fact just a description of B (the shadow cast by the light of science). Also note that some of the vocabulary used in the first sentence isn't in most dictionaries which results in the number of (sometimes very inaccurate) translations that are available. Btw: The episode is no. 6 of Season 1 with Kurogane appearing at about 15:00 minutes.
@followernumber1 On that note, Funimation should dub it as well ;D! I've already watched the show, but it's good enough to where if there was an english version, i'd re-watch it :D. Plus all the incantations would sound pretty cool in english imo. Going from a light voice, to a dark echoing voice. Pretty awesome ;D!