Gyre Sage and Kami of Whispered Hopes produce tons of mana, but you also have cards like Challenger Troll and Dragonhawk, Fate's Tempest that reward you for controlling creatures with 4+ power and are easily enabled by chucking a couple of counters on your Birds of Paradise
It may be sci-fi, but they have done a great job of making it feel like Magic: The Gathering too
Game Changers should generally be cards that easily and dramatically warp Commander games, allowing players to run away with resources, shift games in ways that many players find unpleasant, block people from playing, efficiently search for any of their strongest cards without downside, or have commanders that are highly unfun in casual games
Is this allowed
Junk tokens being artifacts will further have its upsides in decks of this archetype that use cards like All That Glitters or Cranial Plating
Now combined into Urza, Planeswalker, you have one of the strongest planeswalkers ever printed