An artifact creature, land creature, or enchantment creature returned this way will be a 5/5 creature and will be an Elemental in addition to its other creature types
It also contains one of each of the following unlimited printed booster packs: Legend of Blue-Eyes White Dragon Metal Raiders Spell Ruler Pharaohs Servant Labyrinth of Nightmare Legacy of Darkness
Attune with Aether: [Category 3] ETB yield is 2 Energy for 1 mana, then you get a basic land from your deck
I love Rule of Law effects
The idea, according to Matt Tabak, is: The creature ducks out of action for a while and trains, and when it's big enough, you can go on the offensive. That means that the ability needs to be at sorcery speed flavor-wise
Funny enough, though, this is a great example of an era where the cards might not hold up quite as well today