Yeah literally, just turn their brain into an acorn, she can kill omni man and every vitramite. Sure she made a mistake making a park without consulting the city and experts about the logistics, so easy way to fortify earth, is work with cecil to make a giant barrier or extremely powerful weapons. Or city planners and engineers to build shit in africa or something if she is more into that.
Change his organs into candy, swap is brain for a shoe, turn his bones into liquid, or if she wanted to be humane make his limbs fall off.