destructive
dɪˈstrʌktɪv
adjective
causing great and irreparable damage.
the destructive power of weapons
devastating,ruinous,disastrous,catastrophic,calamitous,cataclysmic,pernicious,noxious,environmentally unfriendly,harmful,damaging,injurious,hurtful,wounding,violent,detrimental,deleterious,disadvantageous,ravaging,crippling,savage,fierce,brutal,dangerous,fatal,deadly,lethal,death-dealing