Luigi's Mansion is a bad stage for Lucario? I thought it was good:Good: Yoshi's Island (Brawl version)
reason: Wall-cling recovery is almost too easy, bigger boundaries help lucario live longer overall (although roof is a bit lower than I'd like), and platform is perfect for camping tactics/ SH aerial attacks.
Good: Frigate Orpheon
reason: Some of it is wall-clingable, platforms make it easy for lucario to get a foothold against better campers, ideal for SH aerials with the platforms, high ceiling makes it hard to kill lucario vertically
Good: PS1
Reason: Good platforms, good AS friendly stage, decent ceiling.
Good: Luigi's Mansion
Reason: Semi "cave of life", good area for "Extreme-Awesome" (if you do use this), fsmash rules here (at the bottom, they can't effectively jump over it if they're approaching), and high ceiling.
Bad: Corneria
Reason: Incredulously low ceiling (like MK kills you in 40% kind of ceiling [lol jk]), back wing also lends itself for early kills (not good for lucario who needs the boost), and the slopes mess with AS a bit.
Bad: Rainbow Cruise
Reason: Platforms make it tricky for anyone with a double jump, early kill sides, and anyone with a better aerial game ***** lucario on this stage.
Bad: Luigi's Mansion!?!
Reason: Olimar kills you on this stage with his camping and pressure, MK is just a beast on this stage.
I don't remember the others that are "extremely bad", but I hope you get some of the idea.
http://www.smashboards.com/showthread.php?t=187501
Apparently they also say that Jungle Japes is a good Lucario stage and Green Greens is another bad one for Lucario. Would both of these by any chance, refer to the height of the ceiling because Lucario is kinda easily KO'd vertically? I'm pretty sure that there should be more reasons why though...