Given that they speak of "evil numbers", I think it is reasonable to assume that the Shamans did not understand how the algorithm works. The inventor may have, but it seems likely that the users did not.
Or maybe that the language translation is imprecise.
Also there are "apocalypse numbers" http://mathworld.wolfram.com/ApocalypseNumber.html , "beast numbers" http://mathworld.wolfram.com/BeastNumber.html , "leviathan numbers" http://mathworld.wolfram.com/LeviathanNumber.html , and "legion's numbers" http://mathworld.wolfram.com/LegionsNumbers.html among others.