While Child of Alara is still a powerful commander, this 6/6 for WUBRG (One White, Blue, Black, Red, and Green mana) and its ability to destroy all nonland permanents upon death, isnt all that exciting
We may even use your question in a future article
1 Time Walk Time Walk is one of the cheapest and most powerful cards in M:TG history
Then if an opponent controls more creatures than you, put a loyalty counter on Garruk, Unleashed
With that said, when a deck is built optimally, a fetch land could theoretically grant you access to any color of mana desired at the time it's sacrificed
The new cards interact with each other in ways they didnt previously in The First Chapter