Actually, I only need an advice on who, how, on which site or mail may I question Blizzard such a bit weird question.
I remember from ptr testing of LK some datamining - there were abilities with such names and descriptions:
Red/Blue/Green/Black beam - channels blood/frost/unholy/death force into Arthas. I strongly suspect that this was to be a phase, perhaps heroic only, but was removed, alas.
Also, in his sound files of the battle we found "bow down before your lord and master" and "Apocalypse!" - the last is exactly the phrase he said when channeled a spell at Tirion at Light's Hope. This spell was likely to be added to the fight, but also removed later.
And also a question if anybody knows - how does the phase inside Frostmourne work, in heroic? When do ghosts explode, when they catch players, or at any case? It's hard to see on a video.