A country that celebrates a national holiday every 10 years by abducting a random guy, lock him up for a full year as they parade him around, and the forcefully returns him regardless of his own wishes? Not to bash on anothers culture, but this sounds about as mean as human sacrifices, except just way way more likely to blow up in their face (if they parade him, he is not quite exactly a prisoner, but rather someone they want to follow a script). And that is even before considering the guy somehow gaining powers enough to actually fight back.