From what I've seen, the Admiral makes no claim or otherwise uses the souls he brings here. I've no doubt it could obscure such activity from me if it desired, but it seems clear it has no care if we understand it's motives and purposes or not.

Additionally, it seems to me that the Admiral has no use for souls as items or as specific currency - it does not remove the soul from the body, after all, and there are some here who have no soul at all, me included.