Merlin's Legacy -- The Young Dragons: Blood Moon

It is a time of magic, spells, visions, warriors, and mythical creatures. It is the time before... when a king is yet to be born and a sorcerer's power lays beyond in the mists of Britain.
By the year 475 AD the last Roman Counsel had left Britainia, plunging the Roman outpost into chaos under the rule of a ruthless pretender, Seren Severus. The General of the Legion, has cut a bloody swath across the land, enslaving those who are not slaughtered. After a brutal attack on their settlement, Keira Annan and those of her people who are left alive are forced to flee with little more than the clothes on their backs and their wounded.
A healer, Keira Annan, possesses the gift of fore-knowledge, the ability to know a thing before it happens, and an unusual skill as a healer. She is bound to the future, of a king who will find his destiny in a sword encased in stone. But now, her life and those of her people are at risk from the Legion and foreign mercenaries as they flee into a dangerous and uncertain land where the only value to human life is the price that can be had at the slave market.
Morgan Severus was once the General of the Legion. He was born into privilege and wealth to the daughter of a warlord and a warrior father who was once the Roman Counsel. Now he is far from the power of London and the brother who has exiled him and placed a bounty on his head. He left it all to protect the child who may or may not be his son, and the woman who was once his brother's mistress. After a raid by the Legion on their encampment, all are left for dead.
Only Morgan has survived, discovered by the healer. His life is in Keira Annan's hands, and a people who have every reason to want him dead. But Morgan and Keira's fates are interwoven, revealed in a vision of the future deep in the forest, part of a legacy written on stones in an ancient fortress. If they can trust each other, overcome the wounds of the past and end the rule of a brutal overlord, their strength, courage, and passion will burn through the blood of a future king... a son named Arthur.