Against the Serpentfolk

From publisher blurb:

Captured by the serpent folk, the heroes find an unlikely ally – a mummified-yet-living being from the distant past. Cut off from the outside world, and stranded in the wilderness of Yilan, the heroes must rely on wit & grit to survive, building themselves a stable base out here in nowhere. But they must also bring the fight to the serpent folk, who relentlessly seek to destroy them, raiding with dinosaurs and worse. In addition to raiding the heroes and their friends, the serpent men are not idle – they now begin to awaken other terrifying civilizations from the distant past, forging an alliance that may turn time itself topsy- turvy.