This would be what I consider good addition to sins of a solar empire.
Abstract AI difficulties: Considering SOASE:R has already adopted unnatural AI difficulties, it cannot hurt to introduce a difficulty never seen before in Strategic history: Mirror, Window and Dark Mirror and Shadow.
Expected behaviors on Mirror Difficulty and purpose:
-AI attempts to mimic the players play style during the game or any previously played games on this difficulty.
-AI is actively updating and overtime the AI learns everything you know and will abuse your own tactics against yourself
-This game may challenge players to improve already existing tactics or start a new one entirely, and truly test if you can beat yourself at your own game.
-copy your building placements and upgrades if the planet type is the same.
-Tech level is always at par with your tech level this game or previous games.
-Different races would be hard coded till the player has tried the race. (Recommend to play with only matching factions or factions you have previously played as)
Expected behavior on Window and purpose:
-You have a already existing hard coded AI combined with a faint reflection of your playing style
-This difficulty is slightly more unpredictable even if the hard coded aspects of the AI is clear to you.
-Expect both good or bad improvements to the AI play
Expected Behaviors on Dark Mirror Difficulty:
-The AI is hard coded to build a counter ship every time you build a ship, and has huge credit income bonus.
-Again, the AI may attempt to mimic you at the best of its abilities.
-the AI will produce on its own if they have a surplus of resources and the player seems to be unproductive.
Expected Behaviors on Shadow Difficulty:
-This game mode utilizes all data from Mirror, Window, Dark mirror and Shadow games. By the time you play this difficulty it would be completely unrecognizable depending on how often you tried the other difficulties.
Note: Maybe the AI could learn from replays while you watch them in hopes that they will challenge your knowledge of previous games.
All this AI coding would be a satisfactory DLC on itself.