The blinding knife

Fantasy. Gavin Guile is dying. With fifty thousand refugees, a bastard son and an ex-fiancee who may have learned his darkest secret, Gavin's got problems on every side. As he loses control of his magic, all magic is running wild, threatening to destroy the Seven Satrapies. The old gods are being reborn. Their army of color wights is unstoppable, and the only salvation may be the brother whose freedom and life Gavin stole sixteen years ago.