Many of you suggested Light: may I ask you why you consider Light to be more fitting than Fire? To me, it's even less fitting, theme-wise, so I'd like to understand your point of view.
I had suggested Light for two reasons at the time; it is the weakest element, and it has the worst creatures, so it would benefit from being able to use the creatures of other elements. Another argument for light that I thought of just now is that Light has the most 'other' cards that do not require light to use; photon/rol, holy flash, and luciferin/ase. That would suggest that light is geared somewhat towards being used in conjunction with other elements, like fire with immolation and entropy with nova.
Thematically, I think the card would probably fit best in Life, because life is, in my opinion, the element of pure creature power, since it has nothing else. It would also fit well in aether, because aether is geared towards making use of the other elements as well in an indirect way with twin universe and mindgate.