The two-drop will equip our Commander or another legendary for three and then Knights for seven
If you firebend later in the turn, then when Avatar Aang's ability resolves, he'll transform since you've done all four this turn
I also really love the idea of making Taunting Kobold or Minion of the Mighty the Ring-bearer, letting them attack for great effect and not worry about being blocked
For a whopping four generic mana and three white mana, players can also cast From Father to Son from the graveyard for its Flashback cost, but instead of putting a Vehicle into their hand, they can cheat out any Vehicle of their choice from their library to the battlefield with seven mana
In some cases that may be better for your opponents rather than giving you some creatures or extra cards from your library
Abilities that trigger whenever a creature enters won't trigger