Cannot be Special Summoned from the Graveyard. If this card was destroyed by battle and sent to the Graveyard, this effect activates at the end of each of your opponent's Battle Phases: Discard 1 random card from your opponent's hand. This card must be in the Graveyard to activate and to resolve this effect.
Only reasons I can think of: Wasn't destroyed by battle, or it was destroyed by battle with a monster that negates effects of monsters it destroys, or had an equip spell like the Baou Sword to do that.
Looking forward to adding this card to my Shadow Game/Draw Sense - High Level stall decks. This with soul exchange set, giving it a high chance to get destroyed by your opponent could be cancerous. Then again it could also be highly gimmicky but I'm going to play test it anyway, at the very least it'll be a fun card.