One card I created was the following: Fighting Spirit 1WW Creature Spirit 2/1 Flying Whenever a mystic spell is played, CARDNAME gets protection from the color of your choice until end of turn
It is much less reliable for final rules MTGPress proxy printing became popular because it solved a very specific Magic problem: players wanted a fast way to turn a decklist into printable proxy TLDR Fan-made Magic cards feel real when they follow the same invisible rules that make official cards readable, balanced, and playable
The fact that the deck can win at instant speed means the deck is very good at slowing down and playing a long game against counterspells, as the opponent never has an opportunity to tap out, so its hard for them to establish a clock or dictate the pace of the game
Based on community data from thousands of pack openings, here are the approximate pull rates
Finally, we gave the player a secondary way to advance the Story: they could use mana to progress it