3xSwords
Smash Lord
So it seems like the stages come down to this
Ban: Luigi's Mansion, Halberd, Rainbow Cruise, Norfair, Brinstar, Delfino, Frigate Orpheon
CP: Smashville, FD, Delfino, Castle Siege
Luigi's Mansion - Screws up Grab release. The small tight space allows MK to rack up damage almost 2-fold his normal rate and a missed tech could be the difference between a 30% combo and a 60% one (both which are horrible). Besides that MK benefits greatly from this stage, because he will most likely live a lot longer if he can tech and the house is still alive. He can get kinda of an early kill of the top floor with u-throw and generally anytime that you aren't on the bottom floor and he is, you're screwed.
The edge here is also horrible, IMO worse than FD's lip and it's easier to screw up here because the actual edge is hidden from view. DS here is horrible in general, you have noticeable air time if you DS anywhere on the stage. You probably want to destroy the house as quickly as you can, and although this stage gives MK many perks you can still outspace him. Just that the tight space makes it very difficult.
Halberd - Essentially the stage is one big platform and if MK decides to just try and attack you from underneath you only have a couple of options to stop him from doing so. When the stage comes to a rest then it's not as difficult for you. The various stage effects can either hurt you or save you. If you ever unexpectadely get hit by the claw while jumping it's like an auto gimp. You can SDI out of the laser beam so it's not that bad and the big cannon ball you can counter it if it comes down to that.
Rainbow Cruise - Just plain crap for Marth. Even if Marth wins in terms of spacing MK avoids this if he can employ simple hit and run tactics. Every moment a gimp can occur and anytime you are forced to use your DS you can get screwed pretty badly. This is very dependent on whether or not MK screws up or not but we're assuming the MK won't so... yeah. This is IMO the worst stage for Marth and is when you start looking into CP characters.
Not only that but the boat itself is horrible for Marth. MK can dtilt infinite you and he can rack up so much damage from ledge traps. This stage in particular seems as though you're options are greatly reduced when on the ledge.
B/c I'm lazy
Norfair - Planking to the max for both characters besides random gay *** stage effects
Brinstar - Lava, Platform like stage = Gayness from MK
Frigate Orpheon - You can lose before the stage flips because of that stupid no edge right side
In-between
Delfino
This is very interesting. While MK still has the ability to hit you through the stage and get very early kills from the water and walk off stages you have perks as well. If you ever grab release near the walk off edge you have a guaranteed kill. You have a dtilt infinite (so does MK) and the water can be a early spike kill. This is really dependent on what the player feels. If you feel you can take your advantages to the max than go for it, I personally feel that this stage is more leaned towards MK than Marth.
CP's
Smashville - "It's like Final Destination but it has a platform" - Jeremy
Essentially why most feel this is the stage to CP since it's probably the closest you can probably get to FD. Fairly straight forward fight and the platform has minimal influence due to it being moving. Not only can you get a free f-smash if you catch him on the moving platform but you essentially have a 0-death. It's simple if you grab MK and the direction you are facing is the direction that the platform is moving, you're in luck. You can simply walk>regrab out of grab release and then finish it off with an f-smash or DS or whatever to get the early kill near the edge. Situational but nonetheless a 0-death.
FD - Flat stage, nothing that gives you an advantage, nothing that really gives MK an advantage. Unfortunately this is probably the best you can reduce this match up to, a straight forward fight.
Castle Siege - This is actually a pretty good CP. The second transformation has walk off edges which can be an equivalent to a early grab release kill and the third transformation is a psuedo-FD with a gayer edge. The first stage can be a problem as MK can work really well in small spaces and if you aren't careful can get the early gimp to start the match.
The ideal is to ban the stage you hate the most and have a secondary character to cover for the other stages that you couldn't ban. Of course all of you guys are Marth-only right?
Ban: Luigi's Mansion, Halberd, Rainbow Cruise, Norfair, Brinstar, Delfino, Frigate Orpheon
CP: Smashville, FD, Delfino, Castle Siege
Luigi's Mansion - Screws up Grab release. The small tight space allows MK to rack up damage almost 2-fold his normal rate and a missed tech could be the difference between a 30% combo and a 60% one (both which are horrible). Besides that MK benefits greatly from this stage, because he will most likely live a lot longer if he can tech and the house is still alive. He can get kinda of an early kill of the top floor with u-throw and generally anytime that you aren't on the bottom floor and he is, you're screwed.
The edge here is also horrible, IMO worse than FD's lip and it's easier to screw up here because the actual edge is hidden from view. DS here is horrible in general, you have noticeable air time if you DS anywhere on the stage. You probably want to destroy the house as quickly as you can, and although this stage gives MK many perks you can still outspace him. Just that the tight space makes it very difficult.
Halberd - Essentially the stage is one big platform and if MK decides to just try and attack you from underneath you only have a couple of options to stop him from doing so. When the stage comes to a rest then it's not as difficult for you. The various stage effects can either hurt you or save you. If you ever unexpectadely get hit by the claw while jumping it's like an auto gimp. You can SDI out of the laser beam so it's not that bad and the big cannon ball you can counter it if it comes down to that.
Rainbow Cruise - Just plain crap for Marth. Even if Marth wins in terms of spacing MK avoids this if he can employ simple hit and run tactics. Every moment a gimp can occur and anytime you are forced to use your DS you can get screwed pretty badly. This is very dependent on whether or not MK screws up or not but we're assuming the MK won't so... yeah. This is IMO the worst stage for Marth and is when you start looking into CP characters.
Not only that but the boat itself is horrible for Marth. MK can dtilt infinite you and he can rack up so much damage from ledge traps. This stage in particular seems as though you're options are greatly reduced when on the ledge.
B/c I'm lazy
Norfair - Planking to the max for both characters besides random gay *** stage effects
Brinstar - Lava, Platform like stage = Gayness from MK
Frigate Orpheon - You can lose before the stage flips because of that stupid no edge right side
In-between
Delfino
This is very interesting. While MK still has the ability to hit you through the stage and get very early kills from the water and walk off stages you have perks as well. If you ever grab release near the walk off edge you have a guaranteed kill. You have a dtilt infinite (so does MK) and the water can be a early spike kill. This is really dependent on what the player feels. If you feel you can take your advantages to the max than go for it, I personally feel that this stage is more leaned towards MK than Marth.
CP's
Smashville - "It's like Final Destination but it has a platform" - Jeremy
Essentially why most feel this is the stage to CP since it's probably the closest you can probably get to FD. Fairly straight forward fight and the platform has minimal influence due to it being moving. Not only can you get a free f-smash if you catch him on the moving platform but you essentially have a 0-death. It's simple if you grab MK and the direction you are facing is the direction that the platform is moving, you're in luck. You can simply walk>regrab out of grab release and then finish it off with an f-smash or DS or whatever to get the early kill near the edge. Situational but nonetheless a 0-death.
FD - Flat stage, nothing that gives you an advantage, nothing that really gives MK an advantage. Unfortunately this is probably the best you can reduce this match up to, a straight forward fight.
Castle Siege - This is actually a pretty good CP. The second transformation has walk off edges which can be an equivalent to a early grab release kill and the third transformation is a psuedo-FD with a gayer edge. The first stage can be a problem as MK can work really well in small spaces and if you aren't careful can get the early gimp to start the match.
The ideal is to ban the stage you hate the most and have a secondary character to cover for the other stages that you couldn't ban. Of course all of you guys are Marth-only right?