Each time you search your deck for one or more cards, you can find Omnipresent Impostor in place of one of those cards. If you search your deck for more than one card, you can replace each of those cards with an Omnipresent Impostor as long as there are enough Omnipresent Impostors in your deck. Continue resolving the search effect with Omnipresent Impostor in place of whatever card it replaced. For example, Sakura-Tribe Elder’s activated ability lets you put an Omnipresent Impostor onto the battlefield tapped, while Goblin Engineer’s enters ability lets you put an Omnipresent Impostor into your graveyard.