Well, technically, Jissei is supposed to be the god of evil as a matter to BE overcome, rather than evil that is overcoming. The misfortune and obstacles of life meant to make us stronger.
Though, if you truly do want an outbreak of horrid, hideous, unspeakable evils...sin amok, plague, pestilence, misfortune, monsters, mass chaos, death, destruction...eh, I'll see what I can do.
“…Judge not what a man has done, but judge what he could have done if he was a different bloke altogether. For art thou a leper? And a leper can changeth his spots…” --Rudy Wade, Misfits (Series 4, Episode 8)