Answer:
When set loose I fly away. Never so cursed as when I go astray.
I cut through evil like a double edged sword, and chaos flees at my approach. Balance I single-handedly upraise, through battles fought with heart and mind, instead of with my gaze.
A doctor might remove one from the neck of a Dracula victim.
Die without me, never thank me. Walk right through me, never feel me. Always watching, never speaking. Always lurking, never seen.
I can be cracked, I can be made. I can be told, I can be played.
What do you purposefully put lots of in and on your body, but run away from when you encounter it outside?