I checked out the game you mentioned. It's quite good graphics wise, but the shooting controls drove me mad.

>General Ideas for the game

That arena combat scenario you mentioned sounds hot as fuck to me. As long as it is possible to fight then rape then brutally execute my enemies.

Oh, a bonus level where you just slaughter female slaves for the amusement of the public and yourself would be god tier.

>Requests for animations

a beheading animation or a head bash with a mace, while the girl is giving you a handjob or after you come on her (one of my major kinks atm)

The game you mentioned you could use assets from does a decent job with the kinky attires, but it could be better imo.