Evil in nature (6)
I believe the answer is:
malign
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">evil in nature</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for malign that I've seen before include "Vilify, denigrate." , "Bad-mouth" , "Speak bad of" , "Laming in harmful way" , "Defame; harmful" .)