Its not part of the Power Nine, but by definition, it is overwhelmingly powerful, which is probably why it made its last stand in Revised
These are not just any buildings, however, as asch_win clarifies that the purple and yellow background building actually appears to be Pokmon FireRed and LeafGreens Celadon City Department Store
Outside of these environments, Urza can still be quite good, as he generates 2 bodies for 4 mana, provides a mana sink with a powerful payoff when needed, and can even turn things like Equipment and Sapphire Medallions into tools to race ahead of your opponents while still employing their inherent value
In the popular Amethyst/Emerald deck it lets you pull off a nice little trick with The Queens Castle Mirror Chamber, as you can choose to move a character to castle first, then resolve the lore and draw
If a card refers to "your commander," it refers to both, although if it's trying to perform an action on your commander, like put it into your hand, you choose which one it's talking about