[Glorantha] Elemental Progression and Hepherones' Philosophy

I was wondering, assuming that Hepherones' Elemental Philosophy is correct and there is a sixth element, where would this fit in the Elemental Progression? Would it instead be a kind of neutral "axis 'pon which the others turn" sort of thing or would it take a place in the cycle, conquering one element while being conquered by another? Or wouldn't it fit in at all (thus showing that the Philosophy is flawed)?

--
John Machin
"Nothing is more beautiful than to know the All."
- Athanasius Kircher, 'The Great Art of Knowledge.


------------------------------