A pretty simple and easy to set up combo involves three cards: Trade Routes Mystic Sanctuary Time Warp With these three cards you can cast Time Warp to take an extra turn, either play or bounce Mystic Sanctuary back to your hand with Trade Routes, get Time Warp back, repeat every turn until you draw your win condition
There is a companion mobile app featuring a complete card catalog, where players can keep track of their card collections and wish list of cards they hope to add to their deck
Now, contrast these Inventions with all of the Zendikar Expeditions: most of them had minor effects on the game, with the strongest Limited Expedition being [casthaven]Ancient Tomb[/casthaven] (an insanely powerful card, but nothing compared to [casthaven]Sol Ring[/casthaven])
Some of these cards rise above the rest, with unique abilities, huge HP, and solid attacks
Quick Study: Instant-speed Divination has to be worth something to someone, even if three mana for two cards is a little steep in Commander