The Tech 3 is cute, but wierd. I get what you were going for, and it has some potential, but there are some odd situations some of those pandas create.
Mari Dori should probably say “Reveal a unit from your hand then discard it. Mari Dori becomes a copy of that unit until the end of your turn.” The bit about pretending should be flavor text.
The thing that is wierd, is that you are playing a tech 3, and it creates a relatively weak token that can become a copy of another tech 3. One idea that immediately sprang to mind was I could play G Panda and then reveal a pirate gunship for mari dori to copy. Or Ebbflow Archon, or the more powerful tech 2s, like Hyperion. Tech 3 is generally speaking, a power level intended to end the game, it just seems wierd that one of the best strategies for G Panda is as a way to avoid the tech lab for a different tech 3.