OK, tried F6 Tempest, Omnitron-X, SkyScraper and Chrono-Ranger vs. Ambuscade in Wagner Mars Base. Chrono-Ranger did nothing but draw, but did discard a lot to get rid of environment effects.
Looking through the 8 unlock logs and 4 fail logs listed in this thread, I can see the following:
- All the passes are CR and Tachyon vs. Ambuscade in Wagner Mars Base. Every Tachyon but the base Tachyon was used in the logs, but there are reports of base Tachyon being used in the unlock.
- All of the passes do not have CR deal the final damage.
- none of the unlocks have a bounty in the trash.
- In at least one of the passes, Ambuscade ended the game with "By Any Means" on him.
- In at least one of the passes, Ambuscade ended the game with "Ultimate Target" on him.
- In at least one of the passes, Ambuscade ended the game with "Kill on Sight" on him.
- In at least one of the passes, Ambuscade ended the game with "Dead or Alive" on him.
(At this point, I stopped checking bounties. I think we can safely say, putting bounties on Ambuscade is not an issue.)
- In at least one of the passes, Jim's Hat was in play at the end of the game.
- None of the passes have Hunter and Hunted in play.
-Bounty Board was not played in any of the Passes.
- At least one failure is matching all the above criteria so far. For reference, this is the fail log which has passed all this criteria: https://greaterthangames.com/system/files/forum/attachments/log_40.txt. In this log, only Temporal Grenade, By Any Means and Dead or Alive were played by Chrono-Ranger. These have all been played in passes. One of the passes even has all these cards played. Also, in this failure, Chrono-Ranger did 0 damage. (never used his power)
One thing I noticed in this fail log was that Tachyon did the final damage. That did not happen in any of the other passes. Two of the failure logs cut off, so I can't see who dealt the final blow.
Based on the above data, if I had to take a stab at it:
Defeat Ambuscade at Wagner Mars Base. Tachyon and Chrono-Ranger must be on the team and neither of them may deal the final blow to Ambuscade. No bounty cards may be in Chrono-Ranger's trash at the end of the game. (or possibly, no bounty cards may be in Chrono-Ranger's trash at any time during the game)