I had been running a W/G Heroic deck, and decided it was too straightforward. No one seemed to respect it, even when it was stealing the game from them on turn 5.
After testing W/U/g a little (and loving it, mostly), the green came out in favor of more reliability and predictability. There's plenty of draw power and scry without
Warriors' Lesson
, and
Unflinching Courage
always seemed to hang out in my hand waiting for a 4th land. Without at least 1 mana available, the deck is super-vulnerable to removal. As long as you play it smart and cautious, your heroes will be frustratingly tough to get rid of. I can consistently hold off legacy burn, in fact.
Midway through my testing of the deck, Sage of Hours was spoiled. Now, I realize that he's super-fragile, and will be the target of removal, but check this out: If he gets destroyed, oh well. You have other heroes that were left alive, and your opponent has one fewer way to get rid of them. If you protect him, he lives AND gets counters. It's Win-Win. Paired with a Phalanx Leader, it is comically easy to take extra turns. I played a game with a Judge's Familiar encoded with 2x Hidden Strings, a Phalanx Leader and a Sage of Hours, and ended up taking 5+ extra turns (I won before running out).
Clearly this deck isn't perfect. It relies too heavily on Scry, draw power, and creature protection. I'm open to any helpful critique.