Most people would consider it to be poor sportsmanship, but you technically are allowed to do it
Think of them as a smaller-scale site with an artsy spin
$1.79 Domri, Anarch of Bolas War of the Spark $2.29 Bridgeworks Battle Modern Horizons 3 $0.99 Stump Stomp Modern Horizons 3 $19.99 Neyith of the Dire Hunt Jumpstart $0.79 Grand Warlord Radha Dominaria $1.49 Domri, Chaos Bringer Ravnica Allegiance $0.99 Halana and Alena, Partners Foundations $2.29 Domri, Anarch of Bolas (0098 - Borderless) Bloomburrow Commander Decks Variants $0.35 Domri Rade Emblem Ravnica Remastered $1.49 Arlinn Kord Shadows Over Innistrad $6.99 Rhythm of the Wild Ravnica Allegiance $0.35 Emblem (Domri Rade) Gatecrash 0 results found
And if you copy it, the copy will also be a prototypein this case, the 3/3 version of our Phyrexian Wurm friend
If you are holding Cancel when an opponent casts a spell you dont want them to have, you can respond with Cancel and counter their spell
Any time you flicker a creature (flicker being MTG slang for spells and effects that temporarily exile a creature and then return it to the board, sometimes immediately), it re-enters the game as a brand-new object