Note that under most circumstances, this monster will not be able to search Level 4 Monster Cards (since "Dogu" must be in the graveyard for the effect to activate, and it is itself level 4). However, if you wish to search for a Level 4 Monster Card, you can chain a card that will banish this (and any other Level 4 Monster Cards) from your Graveyard to allow you to search for a Level 4 Monster Card when this effect resolves.
Use this card to attack your opponent's "Ally of Justice Catastor", in order to make this card be destroyed by its effect.
Chain Call of the Haunted to your opponent's field clearing effect (like Dark Hole or Evilswarm Exciton Knight) to resurrect Dogu and allow it be destroyed by your opponent's card effect (make sure the card effect will not destroy exclusively your face-up trap card, or else, Dogu would be destroyed by your own card effect)
This card can be a good side deck card against decks that have a lot of destruction power, such as Artifacts and Fire Kings.