[Redeyes]

The big problem now is that the Arena sees less use than it should (my opinion).

A quick analysis of the arena shows that the risk of participating usually outweighs the reward.
One problem is that the reward really isn't that great nor useful for every participant.
Another that your commander will likely end up dead.

That's why I suggest that the arena be made strictly non-fatal. If the only cost is that one of your commander can do nothing else for a turn the Arena would probably see a near 100% nation participation rate whenever it occurs. A massive improvement from people avoiding it.

Furthermore you could involve giving bonus experience for every fight won, to alleviate "the winner takes it all" syndrome. Which would be a bit silly in the massive mega games around today.