The interface is pretty clunky, but not as bad as Armageddon Empires. So far I've been enjoying it, though I haven't finished a game. I've just been experimenting with various builds for my archdemon.
For those that enjoy screwing with other people there are many opportunities, from the manual:
Kingmaker - Before the game starts, the player with this Perk picks another as his Pawn, who is unaware of this status. If the Pawn wins the game by election in the Infernal Conclave (having the most Prestige at the end of the game), the Kingmaker wins in his place -- regardless of the Kingmaker’s Prestige when finishing the game. The Kingmaker, however, cannot win the game from an excommunicated status (which may be issued through Events or by his seizing, or attempted seizure, of Pandemonium).
The Power Behind the Throne - This Perk allows a player who has become a Blood Vassal to win in place of his Blood Lord (see Blood Vassals & Blood Lords). The Blood Lord must win by having the most Prestige at the end of the game for this Vassal to win in his place. Note: Kingmaker trumps The Power Behind the Throne i.e. If the Kingmaker has chosen correctly but the correct choice would be replaced by The Power Behind the Throne, the Kingmaker is still the winner.
Ritual Masking - If you have achieved a 5th or higher level in the Deceit discipline, you may target any player or any player’s possessions regardless of your diplomatic stance. This ability is called Ritual Masking. You may also attempt to frame other players as the source of this Ritual. You may target other players with Destruction Rituals through Ritual Masking -- even if you and the enemy are outside the diplomatic states of Vendetta, Blood Feud, or Excommunication (the three states in which you can attack other archdemons and take their territory). Masking also allows you to attempt to frame another player as the source of the Ritual. During the Create Order Process, the game will prompt you to declare whether or not you wish to frame another player. Choosing Yes will increase the cost of the Ritual, and if the identity check is successful in avoiding detection, the choice of framing another player will be allowed. Your turn log message will report the name of the framed player.