Alistair’s One by Taylor Rylan

Alistair is almost five centuries old and although he’s had a good life, it’s always been lacking something important. His One. Like a shifter’s mate, a warlock’s One is the most important person in their life, and they’d do absolutely anything for them, including sacrificing their own self for the needs of their perfect match.
River’s life changed drastically after his mother died when he was a teenager. Given away to an alpha that wasn’t his mate,
River spent years locked up and abused until one day he somehow managed to escape. A chance meeting with another alpha would change his life and cement his future.
Alistair and River have to figure out the dynamics of their claiming while trying to thwart the looming threat from those after the ones from ancient lines. Will they come out the victors or do the fates have other plans?