A few of my old Easterling cavalry needed to be converted to create a command set, such as the musician, standard bearer and this champion. These are the original metal versions of the Kataphracts.
I believe that his sword was from the fantasy Chaos warrior box. It certainly made him easy to spot, which is very important for knowing the command radius, and if he is the right guy to get into a certain combat.
This Captain was always very helpful in providing a spare might, fate or will point in a key zone!