A Second Mantella? The Colossal Black Soul Gem

WARNING: Spoilers for TES IV: Oblivion Mages' Guild main quest.

In the Mages' Guild quest-line, at the end you face Mannimarco at the behest of the current Arch Mage, Traven. To protect you from becoming a Worm Thrall, Traven soul traps himself into the Colossal Black Soul Gem. He notes that Mannimarco intended to use the gem to capture his soul. I find the naming of the soul gem interesting. We know that normally black soulgems can only capture 1 soul at a time. It would then stand to reason that a Colossal Black Soul Gem could capture more than one. It seems likely that Mannimarco intended to capture both Traven's soul and the Champion of Cyrodiil's.

Why, you may ask? For one, it may be integral to the creation of Worm Thralls or simply to deny them a peaceful death. In any case, we know that Mannimarco made himself the God of Worms by using the Numidium during the Warp in the West. At the time, the Numidium was powered by the Mantella. Is it then so far-fetched as to believe that the Colossal Black Soul Gem was intended to act as a new Mantella, possibly with the ability to capture multiple black souls?

There is always symbolism in using soul gems of such size and magnitude. We need only look at other receptacles such as the Mantella, The Amulet of Kings, Azura's Star, the Warped Soul Gem from Arniel Gane's quest in Skyrim, and possibly the Colossal Black Soul Gem. Whenever souls are involved there is potential for mythopoetic forces to come into play and for enantiomorphs to be enacted. It is probably due to the fact that all soul gems mimic the first soul gem, the Heart of Lorkhan. For as black soul gems contain the AE of a person, so too did the Heart contain Lorkhan's AE.

Further examples of heart-based symbolism can be seen in the well-known Briar Hearts (whose hearts have been replaced with briar hearts), the use of Daedra Hearts in the forging of daedric armor and weapons, human hearts being necessary for the Black Sacrament, Heart Stones reanimating ash and bone, the Amulet of Kings, and finally the stones of Towers (including the sigil stones of Daedric Towers).

From all this, we can see that hearts play an important metaphysical role in the Aurbis and soul gems serve as external receptacles of the AE, whilst hearts store the AE internally. The Colossal Black Soul Gem can now be seen as a new Mantella.

TL;DR: The Colossal Black Soul Gem can probably hold more than one soul (unlike normal soul gems) and this may allow it to act like a new Mantella. Hearts in the Aurbis are powerful symbols and can be seen reflected in soul gems. I posit that Mannimarco wanted to use the C.B. Soul Gem to mirror his ascension through the Mantella.

Thoughts and comments appreciated. :)