I'm putting together a story that centers around a unified galactic government, but I hit a small snag. Blood magic would be the only "supernatural" aspect of the story, and it would be illegal to perform due to its possibly dangerous uses. The way one would perform the magic would be to either use your own blood, or someone else's, and draw a rune on either yourself or your target. Different runes would have different effects.
Anyway! I'm having issues finding a reasonable way to implement this. I would rather forego the easy option of having a god or some unseen force in the background that hand waves the magic into motion. Would nano machines in the blood be a viable option? Using what we would call "gestures" on our current touchscreen devices as the premise for the runes?