A cursory glance at the results of the Modern Open will show a number of familiar archetypes in the Top 8, and most of the attention is likely focused around the innovations that Tom Ross made to Tron. Tom's deck is brilliant, though when I more closely inspected the second place Dredge list, something caught my eye:
Simian Spirit Guide? In Dredge?! I had seen the idea kicked around given how powerful Cathartic Reunion is and how much speed matters, though a second place finish at an Open is very significant. Simian Spirit Guide consistently finds its way into degenerate decks of many different varieties. Amulet Bloom and Eldrazi are two prominent examples of banned decks that exploited the degenerate mana producer in some capacity. The card has also seen play in Goryo's Vengeance combo, which is a much maligned element of the Modern format.
Of course, while SSG fits into a variety of busted strategies, I'm somewhat skeptical of its future in the format. Given that the Elvish Spirit Guide analog basically only ever assists in degenerate things and shows its head in the 75 of many villains, I have found the card's legality in Modern to be dubious. Should it remain legal, I expect to see it continue to pop into various degenerate strategies, and given the string of "no changes" being made to the banlist this is a real possibility. Should the card remain legal as it continues to pop up in more and more archetypes, like Boros Prison (or Sun and Moon if you're into that...) then it strikes me as a good growth stock. This is one that I would definitely pay attention to when we get the B&R update for Aether Revolt.