If I may speak plainly, I believe the two ethers should be given to Meirin and Darius. Alaira has her batteries, so she has little need for the Ethers. While I am certainly not saying that those two are weak by any means, their magic is a greater boon to them in straight combat than Ssarak's is for him (I am not implying Psychomancy is useless in combat either, far from it). In addition, Ssarak has a number of natural advantages (flight and general toughness) that the other two lack. I ain't picking on anyone, this just seems like the fairest and most logical distribution.