At the beginning of your upkeep, reveal the top card of your library. Any opponent may have you put that card into your graveyard. If a player does, Sin Prodder deals damage to that player equal to that card's converted mana cost. Otherwise, put that card into your hand.
Each opponent in turn order, starting with the one after you in turn order, may choose to have you put that card into your graveyard. Once a player does so, Sin Prodder deals damage equal to that card’s converted mana cost to that player immediately and Sin Prodder’s trigger has no further action.