Nah, I don't like the idea. The Arenas are fine when they're done by the professionals.

I agree ^^^

Unless you could just do minor changes like.

weather
day time
Music
color of the sky
sound FX
change the faces in the living forest trees.
add birds or a dragon flying around the Sky temple in MKD.
What guest character is standing in the back ground
Change the stage fatality for the Sky temple = floor, spikes, acid, Piranhas, dragon catches you in the air, or jagged rocks

stuff like that

Basically all pre made stuff that can be turned on / off or changed in an existing stage. Not creating an entire stage from scratch.

I like the Idea but i think it would be good if it were in a seprate Disc!! Have disk 1 be MK7 and Disc 2 can be every chacther in Mk7 but have create an Arena in it! Also have the krpyt in Disc 2 for extra part and Death traps extras for the arena!!