Some Energy cards have to be decent on their own, otherwise Energy is a completely parasitic mechanic on a bunch of weak cards that need each other in order to do anything
This gives you two ways to build the deck, a flavorful Bending Tribal style, or a combo deck that uses an instant like Moonmist to transform Aang immediately and win on the spot
This enchantment has many applications, but what you should be excited about are these: Commanders like Kykar, that generate creature tokens from the Command Zone
The specific four color Jace card that will be leading the deck has not currently been previewed
If so, they can pay life and mana to draw cards anytime a friendly Elf dies
Unless they're absolutely egregious (like Nadu, Winged Wisdom), cards should no longer go directly from legal to banned, and instead will go from legal to Game Changer