The problem is that getting guys and then targeting them is already conditional, so a conditional thing beyond that is a bridge too far
because it's the card that the best players choose to win with, when casting cost is literally of no consideration
During Wilds of Eldraine design, we created 10 uncommon and 5 rare cards that we intended to use in Jumpstart Boosters
And aside from Ancestral Recall, Braingeyser is the most mana efficient way to draw a bunch of cards at once
Brawl Not Legal Vintage Legal Timeless Not Legal Commander Legal Pauper Not Legal Oathbreaker Legal Penny Not Legal Maze's End Land This land enters tapped
Because you get to choose who gets to draw with you, you can make a short-term alliance with one player, protecting you for a few turns or forcing another player to spend a coveted counterspell to put a stop to it