There are so many cards of four-cost or less that can utterly change the game when they hit the field, and Beseech the Mirror just gave you easier access to any number of them
I can't unsee how this is a simple upgrade on one of the archetype's favorites: Sram, Senior Edificer because if you're like me you ignored the auras and vehicles anyway, and adding blue is an improvement
Dragon Tempest This two-mana enchantment gives a creature haste until the end of the turn it enters, and whenever a Dragon you control enters, it deals X damage to any target, where X is the number of Dragons you control
Often beginning collectors will start to recognize fake cards by feel without realizing it, only identifying that the cards feel wrong
This commander feels noticeably powerful in the context of the precon, but I believe that hell also continue to scale well as you make upgrades to the deck