Current state of things:
- Alien Rulers get a 25% chance to trigger a ruler reaction after each action taken by XCOM - free actions and actions in concealment don't count for that.
- Alien Rulers can only appear in untimed, no evac missions (except Rendezvous, Intel Raid).
- Alien Rulers appear significantly later in the campaign then they would in vanilla if you disable the DLC mission - with the mission you obviously control when they start showing up.
All rulers pretty much suffered the same fate: They showed up and were swiftly killed without getting any attack off and without having a chance to escape. Here are the encounters in detail:
- Viper King showed up in the First HQ Assault, September 14th
- Berserker Queen showed up on the 2nd HQ Assault, September 30th
- Archon King showed up during a landed UFO raid, October 19th
Things that I feel worth considering:
- Bad luck protection for ruler reactions: each time the ruler doesn't take a reaction his chance to take a reaction increases by x%, resetting back to 25% when they get a reaction
- Increase ruler reaction chance while Frozen (to get them out of the Frost Bomb quicker)
- Allow rulers to appear slightly earlier in the campaign
- Reduce the time needed for the Autopsy/Proving Grounds project for the rulers/ruler armors - the reward for defeating the rulers is too disconnected from the actual success and there are already too many PG projects and techs to research as it is