Well we all know that rhue somehow absobs auras correct.. maybe the sword enhances this effect to a souldraining level.
Rhue's sword is a red onyx longsword named chakara the souldrainer....

(ripped from MUD)
but anyways rhue's sword auras are
SWORD auras... remember that.
Rhue has originally a slasher and a piercer aura in his sword. Traziun seemed to sense one of them (forgot wich) and helped rhue learn how to use this new aura for his sword. I think it was before the pits somewhere that you learned the flame and wind auras and after slade you got illuminati, pandamaare, blahablaba and shobidobibu.
So if we assume that Rhueäs sword has alwayhs had access to these auras maybe they are truly released by certain event's or by proper training (hence Traziun teaching rhue piercer or smthn).
Or we assume that the sword can absord auras form other swords and therebu become stornger it would explain why Traziun didn't sense the Über auras at first..
Debate now!