Update: A number of our readers have pointed out that the stage actually is from Fire Emblem: Awakening. Despite having played the game, I didn’t recognize it in the slightest.
Super Smash Bros. on the Nintendo 3DS will have at least one Fire Emblem stage, but this one doesn’t appear to be from Fire Emblem: Awakening. The stage in question (above) actually looks reminiscent of one section of the Castle Siege stage from Super Smash Bros. Brawl, but with a number of differences. Director Masahiro Sakurai showed it off last week.
Additionally, Sakurai also highlighted one of the visual changes being made to the game. On Miiverse, he posted the above screenshot, revealing: “A red-black effect now appears when you’re hit by a strong blow. It’ll only appear when you have high damage, so when you see this you’re in trouble—and you’re probably about to get KO’d!”