Dragon Destiny — Helen B. Henderson

Lord Branin of the dragshi, is more than just a man, but two beings -- one a dragon, the other a human. The pair share one body in space in time and are able to change forms with the other at will. From the time Branin's twinned soul, Llewlyn, awoke, Branin knew the freedom of flight. However, being a shifter comes with a price. Branin and Llewlyn are the only two of their kind who have not found their intended mates, despite millennia of waiting... and searching.

The red-haired firebrand, Broch of Ky'Port plans to fill that position in Branin's life -- with or without his cooperation.

For eons, he fears he would never find a woman with her own dragon soul partner -- until one day another's mind touched his.