Free spells can fall into a number of categories, too
Originally intended for checking printing colors and as artists portfolio samples, artists proofs are now popular collectibles
In Standard, she shuts down the Azorius Control decks trying to loop instants
They're generally written "[Cost]: [Effect]." Some keywords are activated abilities and may have colons in their reminder text
The value you get from a card like this while also being such a proactive play is simply unheard of
Urza is a singular win condition for the decks that can play him, capable of stabilizing a players life total, drawing additional cards, removing opposing cards under opponents control, creating creatures, and even generating virtual mana by making additional artifacts cheaper to play