Sorry about the confusion on this guys.
Last week when I added the code to make sure you always retain the best combat experience, I made it so that powers reset when you merge the unit.
There was a “trick” that experienced players know about, where you can merge spent armies into fresh armies and be able to fire the power again. But if you do it the wrong way around, and merge the fresh army into the old army, you lose the ability to fire the power.
I want to try and avoid punishing players for merging the wrong way around.
I thought it was a little unfair that you had to know the trick, and do it right way around, so the simplest thing was to just reset the power no matter what.
So before, you could fire one of the crystal miners, then merge them, then fire the larger unit again. Now you can fire both miners, merge them and fire the merged unit again. (You still have to have all the mana, and you are left with a larger more expensive unit to fire ect ect.)
If what we have now sounds too exploty I could do it so that merging units creates a period of disorganization while the units work out who is in charge.