In a creature-based deck, Radagast essentially makes it so that you will never run out of cards in hand as every creature you cast is more than likely to replace itself with another from the top of your deck
Its probably strongest in Simic, Izzet, and the non-white, non-black shards and wedges, as youre less likely to be able to protect your permanents from battlefield sweepers
The Commander Lands While completely useless outside of multiplayer formats, these are among the best lands possible for Magics most popular format
This, more than any other Magic: The Gathering IP crossover effort in recent memory, feels like more than just an exercise in branding and revenue generation
MUR uses a different visual treatment textured holographic foil across the full card with explicit Mega branding and pulls significantly rarer than SAR (closer to 1 per booster box for the headline Mega chase)
Plus, its a better topdeck when you have a lot of mana or not much life