"a baleful look" "forbidding thunderclouds" "his tone became menacing" "ominous rumblings of discontent" "sinister storm clouds" "a sinister smile" "his threatening behavior" "ugly black clouds" "the situation became ugly"
"black deeds" "a black lie" "his black heart has concocted yet another black deed" "Darth Vader of the dark side" "a dark purpose" "dark undercurrents of ethnic hostility" "the scheme of some sinister intelligence bent on punishing him"
"bar sinister"
