When buying high-value vintage ($500+), strongly consider only purchasing PSA/CGC graded copies
To start, we have a couple artifacts that mesh well with flicker / blink effects: Prophetic Prism is all over the place in Pauper, and for good reason
Looking at one of the games most evil colors: Black
Finally, because there has been some confusion over this, I want to clearly state what isn't a feature: the difficulty
Island Amulet: Sun & Moon - Cosmic Eclipse, Lt
That boast ability opens the door to powerful synergies, like removing the second lore counter from Elspeth Conquers Death over and over so your opponents are permanently taxed an additional on noncreature spells, or forcing Showdown of the Skalds to pump out counters turn after turn