I just went ahead and did the ouro Arc to get him. I tried on a alt with the same thing happened. It's either bugged or Keyes will not give you dimensional warder credit anymore.
So I finished the Keyes I Trial and have the badge for it. We defeated Anti Matter to complete the Trial. Null is still telling me I need Anti Matter for Dimensional Warder Badge? I'm not sure if Keyes trial counts or not ?