I recently discovered a fun card interaction: Caspit’s Playground (Freedom Tower) and Micro-Assembler (Skyscraper). It lets you search your deck for any ongoing (or equipment) card, super useful for some characters.
What are some unexpected interactions you’ve found in the game?
This is an interaction I found last week: If damage dealt by incidental contract is redirected the new target may be dealt the 1 additional energy damage rather than the original target. So in a 5 hero game Wrong Time and Place can turn Incidental Contact into 12 separate attacks against the villain. Add Twist the Either and KNYFE’s damage boosts and this can become 48 damage to the villain at the cost of only 5 unlucky tokens. In the process of discovering this I dropped Ambuscade from full HP to incapped in a single turn.
Another interaction I discovered a while ago but enjoy putting to use is that Hippocractic Oath can heal for 1 extra point if you target The Idealist (or Mainstay/Writhe if thier signatures aren’t out) with Medico’s initial attack due to Sentinels Nemesis Bonus.
Lastly, team up Santa Guise and Freedom 6 Tempest. Tempest can target his presents with his base power (though Guise may not appreciate you returning his gifts).
Hippocratic Oath also works wonders if Medico gets Infected - free healing for someone at the start of your turn? Yes please! :D
Speaking of Infection, that was something I loved about Fixer’s Jack Handle: It negates any self damage.
Wait. What?! That is amazing. I had not idea you could do that.
Speaking of the Jack Handle, this is from the fireside chats. I haven't tried it yet, but it sounds interesting -- give Fixer a second Jack Handle attack for free:
It works quite well. Add Charge or Overdrive or Plague Rat's infection for more fun. Also see Compulsion Cannister and Catch A Ride.
Even more fun?
Mr. Fixer + Dual Crowbars + Friendly Fire. Back when we were figuring out the best strategy to unlock DW Setback, we realized that combo can take out The Operative in one turn.
Throw in Fixed Point, and you've basically won, so long as you can win via reducing HP to 0.
Kinda sucks for Setback, but it's a little fitting that his most broken combo requires him having the everloving hell beaten out of him.
I haven't had my caffeine dose today, so I'm having trouble envisioning it. Is it something like this?
Fixer hits Operative with Dual Crowbars – first strike of the turn (1), hit 1 of 2 (I'll call this Hit 1-1 to keep track)
Friendly Fire activates, allowing Fixer to hit Setback for 2 HP (Hit 2-1) then Dual Crowbars kicks in, allowing Fixer to do a second augmented hit for 2 +1 (Dual Crowbars) + (any other buffs) to Operative (Hit 2-2)…
3 …which activates Friendly Fire again, allowing Fixer to hit Setback for 2 HP (Hit 3-1), which again makes Dual Crowbars kick in, allowing Fixer to do a second augmented hit to Operative (Hit 3-2)…
Is this a never-ending loop that only stops when Setback is incapped?
Yup. Every time you hit Operative lets you activate Friendly Fire again, with the only limit being Setback's HP. Throw in a Silver Lining and even that isn't the limit.
I did this for the very first time recently:
With Fixed Point in play, got two copies of Dual Crowbars, one Jack Handle, one Pipe Wrench, Grease Monkey Fist, Harmony and two copies of Friendly Fire. Was against Gloomweaver with one Zombie in play. Did about 130 HP or so damage to each.
Heard the stories about Fixed Point abuse before, but seeing it with my own eyes was quite the experience!
I just imagine it as Fixer taking a swing with his crowbar, rearing back for a second hit, Setback coming up behind him all "Whatcha dooooin'?" the crowbar rebounding off his forehead and Fixer not really noticing, just wondering why his backhand has gotten so springy.
Well, that’s the end of it right there. 
Doesn't Silver Lining stop the chain? I was playing in the video game and running through that combo when Setback died and Silver Lining rejuvinated him. The chain stopped at that point. Was that a bug?
Silver Lining may or may not stop the chain.
If you hit the a target first and then start the friendly fire chain when Silver Lining triggers you’ll still have the second hit of your original attack to resolve… starting the chain up a second time (if you have a second silver lining that one will break the chain.
If you hit 2 targets first and choose not to trigger friendly fire off the first hit, then Silver Lining will break the chain.
Environment cards that let you discard your entire hand, such as Toxic Seaweed or Rites of Revival can turn Critical Multiplier into a Haka of Battle. Or, if you have multiple Critical Multipliers out, 3x a Haka of Battle.
Fright Train's Incap + Jack Handle.
Fright Train makes Mr. Fixer hit himself, but Jack Handle's effect takes priority and hits the villains instead.
I'm beginning to like Jack handle more and more
Ooh, nasty! :D
Proverbs and Axioms is also fun with Jackhandle, gives you a double attack.
And try giving Mister Fixer a Jack Handle and Cortex Hyperstimulator. Every turn is Overdrive!