Her shadow now loomed over her which cast a dark silhouette that dwarfed her small frame. It radiated an utterly intimidating, ominous presence.
I got the distinct impression that she had as many lives as shadows she stole based on her previous display with the soldier who tried to chop her head off, but it looks like she decided to help us out by culling the army's numbers. However, it's become evident that her ability is multi-faceted. She can either use them as extra lives or sacrifice them herself in order to gain a boost in power- or whatever her monstrous shadow might do for the silver-haired trickster of a girl.
"I'll spank this hag as swiftly as I can, you do your best to survive until then!" she teased with a cute wink, which only served to make her even more nightmarish considering what she'd just done.