:3 He isn't even bad yet, he isnt using his spirit blade thingy, only one of the two normal weapons he carries around. Consider what he is doing now bad then wait till he go "mlg" pro or whatever. Well, you can attempt to nuke him. He'd die certainly if it hit him, he is only realy mortal, not sure if the pillar of light that strikes people down can strike him anywhere on earth or something. 

"Because killing people isn't nice, especially if he could just disable them. What a bad person." -ERode 2014 before pondering killing Grimm.