With the right chain of rituals, we build towards Blue Suns Zenith, set up a big play with an end-of-turn Commune with Lava, or use pet card of the column, Illuminate
Explore Explore is a cantrip/ramp spell
Asmodeus the Archfiend Auntie Blyte, Bad Influence Henzie "Toolbox" Torre Jalum Grifter Lorcan, Warlock Collector Mahadi, Emporium Master Raphael, Fiendish Savior The Beamtown Bullies Zurzoth, Chaos Rider
Card not found is sometimes seen in various sacrfice decks (or more colloqually, Cat-Oven decks), Evelyn is often the top end of vampire decks and Card not found sees some amount of play in Modern, but not really in other formats, weirdly enough
Latias Star is actually more valuable than Latios Star
The real danger comes from how repeatable proliferate can get