Adjektive
deadly [ deadlier/more deadly ; deadliest/most deadly ]
lethal [ more lethal ; most lethal]
pernicious [ more pernicious ; most pernicious]
murderous [ more murderous ; most murderous]
ruinous [ more ruinous ; most ruinous ]
malignant [ more malignant ; most malignant ]
baleful [ more baleful ; most baleful]
baneful [ more baneful ; most baneful]
destructive [ more destructive ; most destructive]
pestilential [ more pestilential ; most pestilential]
truculent [ more truculent ; most truculent]
withering [ more withering ; most withering]
abolishing {mil.}
eradicating {mil.}
exterminating {mil.}
annihilating {mil.}