(The copy becomes a token.) A resolving copy of a permanent spell becomes a token, so the token isn't "created." Effects that care about a token being created won't interact with a token that enters the battlefield from Mendicant Core's last ability
Now fixtures of Sapphire and Amethyst decks, the combos you can pull off with the right moves are dizzying: Goat Merlin on the board for one lore
Left out of the decks inclusion of cards that trigger when you draw your second card, Minn can help your board go wide with ever-growing Illusions
In Commander, however, where fast mana is absolutely everywhere, this card can be played surprisingly early
A lot of plansewalkers are good because they offer utility, either value or removal that can turn into a threat
LIBRARY OF CONGRESS Land Library of Congress counts as a basic land