A spar room would be neat!
(If u dont know what Spar is, it's a 1v1 arena and u can access into the fight just by signing in the spar list and fight after other people's fight is over)

1 spar room's entrance will be in bazaar, or u can just teleport by pressing the "Join Spar" button right at the coliseum page.
In the spar room, there will be an icon/button for signing in for the fight, right at the bottom of the screen (and in the coliseum page). Signing in for the spar will be 50cr. There will be a list in the coliseum page (when inside the spar room) that tells u who will be fighting next or right now. In the spar room, there will also be some options in the coliseum page. The option allows u to decide who u will be fighting with. It will allow u to only fight with 1*-5* geared player, or only with ur friend. There will also a spar history in ur SK in-game profile. A spar history that tells u how many times u have win and lose, and who u ever fight with (max 50 people on the spar history list). Winning a spar will give u 60cr but losing a fight will give u -50 cr.

I was inspired this idea by these games (made by the same company/people) : Graal Classic, Graal Era, and Graal Zone.