Merciless one (4)
I believe the answer is:
ming
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">merciless one</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for ming that I've seen before include "Chinese dynasty noted for porcelain" , "An imperial Chinese dynasty" , "Mediaeval Chinese dynasty, ware" , "Porcelain associated with Chinese dynasty" , "Famous porcelain from China 14th-17th centuries" .)