Exiled cards are exiled face-up in most cases unless the effect says otherwise
Nalia's ability to cast cards from the top of the library and pump for her party doesn't do enough to make up for that
Pride of Lions, by the way, has some hilarious art that looks like it would be on a silly retro t-shirt you might find at a thrift store and thing, "How did this get made?" Seventh Edition also had some really great pain lands that tap to add one of two mana colors by spending one life, or generate a colorless mana without the life cost
In this case, Hiram Flaversham and Fortisphere weren't exactly "game-breaking," but they did force competitive play into one specific niche, rather than allowing for diversity and balance
In Modern, she would have been playable in the right deck
Marcus, Mutant Mayor Simics no stranger to +1/+1 counter commanders