Key to the City is nifty in that you can use it to discard an Equipment card that you can reanimate with Ratonhnhaktons ability, and later on it can even draw you cards
This means cards like Circle of Dreams Druid and Growing Rites of Itlimoc are good payoffs
With Ranar the Ever-Watchful as your Commander , you can create flying spirit tokens whenever you foretell or exile a card, steadily building board presence
(Source) Endymion's Pendulum Effect does not count Mythical Beast cards in your Pendulum Zones
On top of that, if you control four or more humans, each of them gets an additional +2/+2 buff, which can quickly turn the tide of the game and often becomes a game-ending threat
The main difference from other card games is that its mostly single-player, and that means no additional costs to the game besides the base cost