Waiting for someone to make a fan card called Tie. In a similar vein as tower, this card empowers 2-card combos. But this works only with two Action cards. So think Native Village/Brigde rather than Ironworks/Gardens. And, certainly, engines engines engines. We have seen that Bandit Fort makes BM terribly bad, but when you think about it, the point swing from this in an engine vs BM game is almost as bad.
And it's another card that requires lots of tracking to play well. You need the number of your own and your opponent's top two most common Actions (sometimes even the top 3).
There is a comparison to Palace to be made, because this wants you to collect sets of 2. It is in that regard more powerful than Palace, and more flexible as you may choose which cards to collect, but a bit limited. Outside of weird edge cases, this will never score more than 30 VP, and that's already rather unrealistic.
Some interesting cards to interact with this, in no particular order: Rats, Stonemason, Scyring Pool, Ironworks.
The interaction with Triumph is unfortunately rather limited.