The Lost Monster Hunter Returns

When ten-year-old Erling, the son of legendary hunter Karl, is kidnapped during a beast raid, his memories are erased with a forbidden elixir and he is replaced by another boy. Renamed Viggo, he grows up as an abused thrall while the imposter Gunnar is raised as Karl's beloved heir. Eight years later, Viggo enters the Hunter Trials to win his freedom, unaware he is fighting beside the father who has searched for him for years.