Jace's Triumph
Sorcery
Draw two cards. If you control a Jace planeswalker, draw three cards instead.
His triumph was not in outsmarting Bolas's plan, but in understanding why ultimate power is self-defeating.
Illustrated by
War of the Spark#55UncommonEnglishLegality
Rulings
May 3, 2019
Whether you control an appropriate planeswalker is checked only as the spell resolves.
May 3, 2019
Controlling more than one planeswalker of the appropriate type won’t have any more of a benefit than just controlling one.