If you were really a pyro, you'd know what a solid oxidant was. But anyhoo, if your strict requirement is that they get oxidated, and the only tool is space magic, then the answer is simple: nuclear fusion. Living things are made out of carbon, oxygen and hydrogen. You fuse some of the hydrogen (1) with some of the carbon (6) to make oxygen (8), and use the energy from the mass defect to ignite everything that's left.