He Who Finds Mercy Series by Katy Huth Jones

The pretender king and the lawless regency council are no more. The surviving people of Levathia gladly enthrone the rightful king and struggle to rebuild in the aftermath of the land's terrible losses. A remnant of the great dragons returns to assist the new king. But there is another dragon under the control of the witch Edrea and the one surviving member of the former regency council who feels he has nothing to lose by unleashing this dragon's fury... moreThe pretender king and the lawless regency council are no more. The surviving people of Levathia gladly enthrone the rightful king and struggle to rebuild in the aftermath of the land's terrible losses. A remnant of the great dragons returns to assist the new king. But there is another dragon under the control of the witch Edrea and the one surviving member of the former regency council who feels he has nothing to lose by unleashing this dragon's fury. He will complete his revenge upon the House of Alden, or set the land on fire. less