I'm not sure that they are legal in MTG tournaments
from the Magic: The Gathering Tournament Rules
3.3 Authorized Cards Players may use any Authorized Game Cards from Magic: The Gathering expansions, core sets, special sets, supplements, and promotional printings. Authorized Game Cards are cards that, unaltered, meet the following conditions:
• The card is genuine and published by Wizards of the Coast
• The card has a standard Magic back, is a double-faced card, or is a card that is part of a meld pair.
• The card does not have squared corners.
• The card is not a token card.
• The card is not damaged or modified in a way that might make it marked. • The card is otherwise legal for the tournament as defined by the format.