So, with the base game I used the Staged Aliens variant, so I could see more of the aliens in each game, and to prevent being overrun in the early game without making the game too easy. Evolution added several new aliens, so that variant needs some reworking.
There's another thread in this forum about doing the same thing (here), but it's more complex than I'd like and focuses on replicating the introduction order seen in the video games, which I think is largely unnecessary.
In the original variant, you take 3 copies of each type of alien to make the decks; you started with some of those types shuffled in, and at the end of each turn you would would shuffle in one more type, in a preset order, or two more if you completed a mission. You also would shuffle in one of the types at the start if playing Onslaught, because it had a shorter minimum length to hit the final mission.
There were a number of problems presented by Evolution;
- There were enough types of aliens that you probably would not get the opportunity to see them all if you just added them into the progression
- The new types of aliens did not follow the pattern that allowed cutting all but three copies of an alien; there are 4 distinct varieties of Seeker, for example, and I'd rather not have a "shuffle, remove one, shuffle into deck" sort of procedure.
- The Invasion Plans have changed with the expansion; Onslaught is no longer quicker to the Final Mission (getting it at earliest during the fourth turn), and Annihilation is actually a turn slower, so that correction point isn't needed.
As a result of these, I decided to use all seven copies of each alien (9 for drones); technically, that means your chance of drawing a later of alien goes down a little, but it's a marginal difference; and I decided that the "starting deck" would have Mutons and Drones in addition to Sectoids, Floaters, and Thin Men.
So, the variant;
At the start of the game, do not create the enemy deck as directed in the app. Instead, separate out each variety of alien, and shuffle together the Drones, Sectoids, Sectoid Commanders, Floaters, Thin Men, Mutons, and Muton Elites.
At the end of each round, shuffle into the enemy deck the first stack from the following list that hasn't already been added. If you completed a mission that round, shuffle in another stack.
Never shuffle the enemy discards back into the deck.