I knelt before the first squall, remembering Arthurs instructions on finding Beast Cores.
Beside the Heart, or inside the head.
The blade of my axe pressed into the beast's chest, and the flesh parted easily, ribs snapping one by one as I sliced open the entire cavity. And there the heart was, small and ugly, and beside it, glowing faintly, a shard of red crystal no larger than a fingernail.
I wrenched it free, rolling it around my bloody fingers as I observed the light. It really was fascinating.
Three more times I carved. Three more times, the results were the same. Four tiny cores, weak light pulsing faintly in my palm, and then they were gone, straight to my Inventory.
Only the Tremor-Class remained, and it's carcass, conveniently, was already bisected. So I went straight in, hands deep in its steaming innards, pulling aside sinew and organs slick with blood. Nothing. No glow.
I scowled, jaw clenching and unclenching, then dragged the axe up and over its skull.