I thought that it might be interesting to play as one of the emperors generals that is currently overseeing the expansion of black marsh. the Argonians would be more feral and vicious than in Cyrodiil or Morrowind And you would have a variety of missions. You would have to report to Cyrodiil for regular reports to the emperor, recruit soldiers or hire mercenaries. deal with argonian tribes or completely take Black marsh to yourself and use the people for what they're worth. Side missions might be aiding the natives and betray the emperor or to go on a genocidal campaign against them, you could have a base camp that can be upgraded against native raids. the argonians arent being wiped out though, they are actually repelling the imperial forces and you must fight them to the death. a much darker and eerie mood for an elder scrolls game would be awesome, i thought oblivion was too cheery and bright, morrowind was a little dark but decent enough.
NOTE: this is a suggestion not a new game!