mtg are secret lair cards legal in commander Deck: Everyone's Invited : Toys & Games Archangel Avacyn | Secret Lair

Examples of non-rotating formats include Pioneer, Modern, and Commander.

Aerith Gainsborough is more expensive, but the built-in lifelink means you probably dont need to worry about where your lifegain comes from

It has been cheated into play by decks using Indomitable Creativity alongside a haste-giver in Pioneer and Modern and even abused for its high mana value in the "Grishoalbrand" combo deck

I think the default will be fetch a basic Plains and make a 2/2 when the battleifeld isn't pushing in any directions, and that's pretty good for three mana

In terms of sheer lore (yes, this is something that I absolutely care about, possibly more than I should), I think the deck works perfectly