Uatu was the first card I got to Infinite, for the first couple of months I played with Uatu in all my decks, as planning for Locations worked out well for a lot of my early decks: it would allow me to Scarlet Witch Locations I didn’t agree with, or play cards before they were revealed.
Eventually I moved away from the Uatu planning model, since when going up the Ranks it is more important to Escape rather than fight for an adverse Locations layout. Most of my decks don’t even kick in until turn 3 or 4, now.
Still, whenever I pull one from an opposing deck early game, I geek out on strats. 
I’ve Infinite ranked Uatu a couple of times, the last I left it as:
I should build a deck around it to finish off that last upgrade…
Comic book nonsense (spoilers)
[spoiler]
Uatu is a Watcher. Was a Watcher. Is now the Uber-Watcher?
Turns out on a long enough time line, any organization in Comic Books will turn into an existential, cosmic fascist organization. 
Anyhow, because Uatu lived on our moon, they were the most important Watcher, and had to kill the others because of their cosmic fuckery.
It’s okay! We have a new Watcher for Earth… Nick Fury.
Comic Books, my friends!
[/spoiler]