A 3/3 for 4 mana isn't too impressive, but when she attacks and you pay , you are suddenly attacking with a 6/6 trample, vigilance creature that pumps all your other legendary creatures
If you use them too often, you may find fewer resources to work with
Life is too short to be anything but happy
Once all players have made their choices, the permanents are destroyed simultaneously
The simplest format for a list of Magic cards is a text file containing the number of copies you own and the name of a card on a line by itself: 2x Mimic 1x Mordenkainen's Polymorph 2x Ray of Frost 4x Sol Ring However, the application supports many formats, including a CSV from Magic: The Gathering Online, TCGPlayer table, MTG Studio, Apprentice, DeckBox, and more
So even innocuous-looking hexproof cards tend to cause problems