no attack at all
I drop a nuclear bomb above the next user, who isn't in a nuclear proof bunker.
However, the detonator malfunctioned, so the bomb failed to explode. I extract the uranium to use as fuel for my nuclear reactor.
I poison the next user with nuclear fission fragments from the reactor.
The radiation turned out to be alpha radiation from a nearby piece of uranium, which is blocked by my skin, so I am not harmed.
The next user is dying from exposure to neutron radiation, which has converted their body into radioactive isotopes.
Antimatter eats up the radiation .
The next user is killed by the fact that he is stuck in school forever with mines under every piece of flooring in the school.
I cloned myself. I was in the meanwhile scoring a bicycle kick in FIFA 13.
Adolf Hitler kills the next user in the Auschwitz-Birkenau Concentration camp.