Game Debut: Various Fire Emblem games
Smash Debut: Super Smash Bros Brawl
Summary of Castle Siege (Smashpedia): Castle Siege is a Fire Emblem stage in Super Smash Bros. Brawl and Super Smash Bros. for Wii U based upon themes and motifs from the series as a whole, rather than one particular title, due to the stage not resembling any game of the series.
When the match begins, players begin the fight on a small section of the unnamed castle’s roof, which is bombarded by heavy fire from catapults. Eventually the floor shatters as the castle defenses waver and players fall into the throne room, which has breakable statues, four platforms and a solid floor with no drop-off points. Two platforms are held in place by destructible statues, just like Luigi’s Mansion, which means that this could cause problems for projectile usage. There are also two hanging cloth emblems above serving as platforms. Players later fall again into the underground, which contains one stone platform balancing on a stone spire in the midst of a lava cavern. A part of this area is slightly elevated. After a while the stage will transition back to the top of the castle.