Check out the Land section of the Jumpstart card image gallary to see which land is tied to which theme
and the Through the Ages bonus sheet is chock-full of EDH staples, from Atraxa, Grand Unifier and Ragavan, Nimble Pilferer to Brainstorm and Force of Negation
No +1/+1 counter will be put on Scavenging Ooze and you won't gain life
If exerted be that through singing, questing, using one of their abilities or other reasons in another players turn these characters can be challenged, requiring the challenger to exert their own card and then resulting in both characters simultaneously applying their strength to their rivals willpower
Artifacts, Saga enchantments, and legendary cards are all historic, so you can get an in-game advantage for playing a deck that honors the plane's rich history
Theres lots of reasons why people like this one