Aside from thematics, the other consideration for element choice is which element will benefit from / needs the mechanic most.
For
there is definitely need for generation of off element quanta, but that is more in the context of ability use, not so much for card playing.
Elements that would probably benefit most from this card in terms of needing to be able to cast off element cards:
(mindgate)
(SoSe, rewound mutants)
(almost all pillar based bows could benefit strongly)
This would certainly be a very useful card in mindgate or SoSe based decks.
With 3 SoSe and 6 of these, you are guaranteed to have the potential to generate enough quanta to play all the cards SoSe generates (barring QC of course).