The nice thing about having a one card combo is that you don’t need anything else. Just draw Scapeshift, and boom! They’re dead. The awkward part of a one card combo is that sometimes you can’t find it. I know I put them in my deck, but they just don’t want to show up. Sometimes casting Peer through Depths four times just isn’t good enough. When you truly need to find Scapeshift, you could transmute for it via Clutch of the Undercity like the Swedes did at Pro Tour Return to Ravnica, or you could cast a playable card like Gifts Ungiven.
Honestly, I’m disappointed this deck doesn’t have an Unburial Rites package to Gifts for. Hall of Fame hopeful Makihito Mihara played a deck featuring Scapeshift and Unburial Rites at Pro Tour Return to Ravnica, and I remember how cool I thought it was at the time. Slaughter Games you? Fulminator Mage your land. In response, Aven Mindcensor!
Alright, Aven Mindcensor is still going to get you. We can’t have it all.
Still, I think Gifts is a solid add to Scapeshift since it allows you to dodge a lot of commonly played hate cards. Adding new dimensions to your combo deck is almost always a good idea.