Soul Crystals are one of the biggest mysteries in the game for me. On the one hand, some of them are super rare, some are not. And they seem to be very easy to make. No one makes a big deal about you being the person who is essentially acting as a template for the BLU and MCH Soul Crystals. Or even that new blank Soul Crystals somehow happened to be on hand.

For that matter, why do deeds have to be "carved" on them? And who does that anyway? And how does doing that help the next person who has the Soul Crystal?