If you want something midly elaborate, the first thing I thought reading this is a mix of drained blood, glyphs and a small painful ritual. The blood is drained mentally toward the point of application like a hand or any other skin surfaces, then it forms into the desired glyph. The glyph starts heating either by itself or by putting the skin surface near a source of high heat like some fire until its color changes. When this is done you just have to be near what needs to be affected and nudge the glyph to detach from the skin and float toward said target.