Similar word to annihilative:

annihilative, baleful, baneful, calamitous, cancerous, cataclysmic, catastrophic, consumptive, cutthroat, damaging, deadly, deleterious, detrimental, dire, disastrous, eradicative, evil, extirpative, fatal, fell, harmful, hurtful, internecine, lethal, lethiferous, mortal