Concept
I had an idea for a Creature-focused deck that was a balance between fun and power with the new Radagast hero. And...holy shit is this card dope. So, I was like, okay, why not pair him with Gandalf for two Istari heroes that can pay for cards out-of-sphere. But both are stupid high cost, so I needed a card to round out the weird rules interaction when you reduce to 0-cost using Radagast's Staff, so the obvious choice was Éowyn; her Setup text is incredible (getting the deck to start at 31 is big), and the starting 4 is so necessary in a build like this one. Then it's really just taking advantage of big G's stat line with Support of the Eagles and readying. I did absolutely build this deck in concert with a mono- deck with heavy cancel, threat reduction, and recursion, but I quickly realized that this deck really can do well on its own if you can play a creature and have both Gandalf and Radagast ready for defense while you set up. The hardest part is managing damage and threat, so you might consider swapping in a couple cards to mitigate those dangers.
Deckbuilding
Included all the toys for both our wizard friends and then a bunch of Eagles, along with Loyal Hound, which is excellent value for both its stats and its Response. There are 4 readying cards for Gandalf in the deck, which helps tremendously in terms of consistency, regardless of cost point. The events are all just card-advantage cards or ways to bounce Meneldor and Descendant of Thorondor for extra nastiness. Steward of Gondor is too good to pass up with a couple copies of Wizard Pipe in the deck, even if it's not explicitly necessary.
Gameplay
The idea is to hard mulligan for Radagast's Staff, as every single ally in the deck is a Creature. If you get a cheap Eagle or a dog, then that's the best-case scenario, as Raddy doesn't exhaust to quest, then. At that point, all your options are open...If you can play another draw card or Word of Command later in the round, do it. Dig for either Shadowfax or Unexpected Courage and a Support of the Eagles. Then, it's really just playing cards, turning them sideways, and having fun.
For reference, here's the deck I wanted to pair it with: ringsdb.com