It also provides useful card advantage, and due to the cheap nature of most Bear creatures, it's somewhat easy to fire off a flurry of Bears from the top of your library
Mana is the most important resource in Magic, and pretty much every EDH deck plays at least a little ramp, with veterans often recommending about 10 ramp cards, though this varies by deck curve and win speed
Yet, thats what we have here with the Black Round Corner Foil Star Filler Card
The difference in staples between EDH and cEDH is notable, with cards like Burnt Offering (actually a Rakdos card) featuring quite highly
Zada, Hedron Grinder Another fantastic deck from Tomer Abramovici
Norn is expensive and has a huge presence on the board, so better protect it as best you can