The way Hemalurgy works, as far as I understand, is the spike sorta latches on to the victims spirit web-- what makes them, them-- and rips off the corresponding chunk of whatever that latched on to. The possibilities here are endless. The spirit web is everything about somebody, including magic and stuff like that. So, stealing a Spren, or stealing BioChromatic Breath, is possible. I would imagine that, since the spirit web makes up everything that a person is, though not physically, creativity could be taken.