Ephemerate is probably strongest in 4c Elementals, where every creature has a threatening ETB that can value-spiral out of control quickly
The Escapist
Ragavan, Nimble Pilferer is so significant against these decks because they generally cannot interact with the monkey, which means it can start generating a lot of treasures and allows the fair deck to cast spells and progress the board while also holding up interaction like Counterspell or Archmages Charm for any potential broken plays
Ill cover what each combination does best, where it struggles, and which formats suit it most
But Ive met players with large enough collections to have multiple binders organized by pricethis binder has cards valued between $5-$25, this one $25-$50, that one only exceeds $50, this ones all foils, and so on
Its even better against Burn because so many of Burns resources are spells and not creatures, so its much harder for Burn to keep up a consistent damage output if they lose a beater