Skull Clamp was the scourge of the tournament scene nearly 20 years ago, but with only one in the deck, it could still be hugely useful
Luckily, there are a few unofficial options built by the community
Whispersilk Cloak also makes its wielder unblockable, making it nigh-impossible to remove outside of using board wipes, or spending two removal spells (one to remove the artifact, the other to remove the creature)
The main combo is related to Perilous Forays, which allows you to sacrifice a creature to put a land with a basic land type from your library into play
Yes, undying works with sacrificing creatures
Firdoch Core in particular is really interesting, as it can take advantage of a myriad of typal payoffs, not least making a Treasure token when Magda is in play