Considering people didn’t (generally) even like the 30-day resetting (Blitz) servers, I doubt there’d be popular demand for this kind of thing. But who knows, it might be out there.
I’d suggest a death penalty. Each time you die, you lose a level and have to re-earn the level. The problem would be spawn campers though. The desert spawn would need a way to keep out anyone with armor or weapons.
The only way I see this working is in a heavy-RP scenario, because then alliances - treaties - etc really start making sense: Going to war is costly, even if you “win”. And a clan-mate getting murdered is a BIG deal. Could be interesting, I’m talking myself into considering this!