@Dark Jack, Shien, and ASTA:

So if the key way we see mortal beings absorbing magical energy be through a magical process, and we see that Del-korm already have rather strange soul make-up (if in fact ASTA accepts that tidbit as reasonable and well fitted for the race) then would it be too far of a stretch to say that the process that allows them to increase the power of their Echoing(magic) by way of absorbing the voice(magic) of another be something that can be attributed to a soul evolution/mutation?

If that's possible/reasonable then why not have it that, for whatever reason, Del-korm have been absorbing the magical energy of their foes for long enough that it has become more or less an inherent, and somewhat automatic, trait for them. Perhaps the trait is triggered by specific circumstances so that they can't just do it willy-nilly, but are instead required to meet those guidelines so that they can increase the power of their voice(magic/souls) via the aforementioned method. Would that be too far fetched?

Idk, I just thought I'd supply my idea since it came up while I was reading over this conversation, which as always has been quite interesting ^_^: