"devilish schemes"
"the cold calculation and diabolic art of some statesmen"
"the diabolical expression on his face"
"a mephistophelian glint in his eye"

"something demonic in him--something that could be cruel"
"fires lit up a diabolic scene"
"diabolical sorcerers under the influence of devils"
"a fiendish despot"
"hellish torture"
"infernal instruments of war"
"satanic cruelty"
"unholy grimaces"