What if you just negate Raiders' Camp but not return it to deck? Do the heroes come back or do they stay there but aren't released and you get the soul?
They are still held in Raiders' Camp, so long as they were there prior to that battle phase. At that point, the placing of the hero in Raiders' Camp is not negateable, so they remain. In addition, they could not be released instead of redeeming a soul, as that part of the ability would also be negated.
However, any heroes captured in that Battle Phase would be returned to Land of Bondage (whichever they were captured to originally) because the placing of the hero in Raiders' Camp would be negated but not the original capture. Other heroes captured previously would remain, but they could not be released instead of redeeming a soul.
But yes, if you return it to deck, the characters return to their owner's deck as well.
