Sirius Black and the Resurrection War

Sirius Black has waited for many, many years beyond the Veil, looking for a way back to Harry. One day, a mysterious stranger offers him a way out, and over a long time, manages to free him. However, Sirius' freedom comes at a price, because he is not the only one to return from beyond the Veil, and not everyone is quite as they were before death... Please review guys! Thanks!