Wizards of the Coast has said that proxy cards are not allowed in competitive play such as sanctioned tournaments
Here's their interface for showing your order in progress: Finally, I got a confirmation email with my order number so I could track it inside their portal
Its not quite Mind Rot, but it gets either two lands or a spell, which is a bit better than your opponent discarding an excess land
Scion of Calamity is a great card for any creature deck, but being a Dinosaur lets it enjoy a bunch of extra synergies in this deck
If some other effect causes Wedding Announcement to have three or more invitation counters on it, it won't transform until the next time its triggered ability resolves
Suffice to say, decks play these lands without downside most of the time, and they shine in 1- or 2-color decks