This card is best activated during your opponent's Battle Phase since you won't have to worry about the drawback and since your opponent's monsters will mostly likely have to remain in Attack Position, you can inflict some damage.
A good combo with this card is to summon a Dark World monster besides Grapha, Dragon Lord of Dark World while you have one in the grave. Activate it during the End Phase of your opponent's turn, then return the monster you summoned to generate some field/hand advantage.
This card can be used to summon "Ceruli, Guru of Dark World", causing your opponent to discard a card. It can then (in your next turn) be returned to the hand to summon "Grapha, Dragon Lord of Dark World" so its effect can be used again.