Of course banned players shouldn't be able to participate. This is easy. As Striken said, ban evasion isn't allowed, it simply goes undetected through day to day activities such as spar and pk because it's frankly hard to catch. In GST however, it's ridiculous that people who have been rightfully banned from the game can play and mess with the integrity of the tournament. This rule was enforced in the past (I felt it myself being part of a team with banned players on alts that was DQed) and it should continue to be enforced. It's like being banned isn't even a problem anymore, can just get on on another account and everything is fine. Ridiculous imo.