Well, since we're talking about stage ideas, I'll throw my two cents in:
There are two different battle grounds in this stage: one is outside and the other is inside.
A match always begins outside; on the roof of Krazoa palace, where Krystal was trapped inside of a crystal (lol, a homonym).
Rooftop Description: Players begin fighting here. There are different little ledges and idols that players can jump onto and battle on, including the giant alter that Krystal was trapped in. After a while, however, parts of the roof break away (because of battle-damage), and if a player falls through, they land on to the next battle ground, the inner sanctuary of Krazoa Palace (players can also fall through the giant hole under the alter if they are not careful).
Inner Sanctuary Description: This is the main room of Krazoa Palace from SFA, the room with all of the fans. Players fall down to here through one of the holes in the ceiling or the main hole under the roof alter. There aren't as many ledges around, but there are two giant fans that can make players hover for a short time. Players can use the fans to get from one side of the battle ground to the other side, or back up to the rooftops if they wish. The fans can slowly move, however, and you have to time the jumpig just right to get to where you want to. Otherwise, you'll fall through one of the pits in the ground.
Hazards: On the rooftop, the only hazards you have to worry about are the temple guardians (the jellyfish-looking things that spin and attack you). The other hazards are the Sharpclaw soldiers (two different types) inside the sanctuary. Other hazards may include any SSE enemies and falling off the rooftops or into the pits inside the temple.
Stage Size: The stage would be similar to Castle Siege in changing layouts, but the overall size would have to be a little bit smaller than Hyrule Ruins from Melee. That way the camera won't get ruined if some players are inside while the other are on the roofs.
SSE Campaign Idea: One of the stages for the SSE campaign, where Krystal is trapped inside the crystal by SSE enemies, and your job is to save her. Once she is released, she joins your team and is now unlocked as a new character. I don't have any idea for the boss though (maybe the giant Krazoa statue?)
That's my idea. What do you think?