Ive made another map, this time a cave mob arena map that would also work good for sumo.
It is made for servers with a mob arena pluggin, or you can spawn mobs in single player and fight them, or even put in spawners and fight until you die.
Ill be adding two more versions of this map, one will be without the glowstone lighting so its a darker version and one making it into a spleef arena.
Hope you download it and enjoy!!!

Also if you do download it for your server leave the IP in the comments please.