Sometimes, the opponent will not even have access to three mana and will be locked out of the game for a long period of time
This ability in itself puts Arcades head and shoulders above any other wall-tribal commander, as an Arcades player will never run out of cards to play, as each wall replaces itself in its owner's hand as soon as it's cast.
Izzet Epiphany is one of the best decks in standard going into this release and Thalia, Guardian of Thraben does a good job of hosing it
[mtg_card]Treasure Cruise[/mtg_card], for example, could be played for one mana, essentially making it like [mtg_card]Ancestral Recall[/mtg_card], perhaps the most powerful card in Magics entire history
It works great in decks running Hardened Scales or Daghatar the Adamant, especially if you want to spread counters around strategically