CHEMO is a Custom:LEGO Bludhaven character.
CHEMO is a toxic creature made by Custom:T.O Morrow who also destroyed Bludhaven. T.O Morrow from the future knew this would happen because it had already happened in his mind. CHEMO is mindless and is controlled by Custom:T.O Morrow so he has no choice but to destroy Bludhaven. Only if T.O Morrow had of pressed the off button, but Morrow knew he could go to the past and fix it ... but he didn't, so that time would've been part of Bludhaven's History.