Why play turn-based games when you can just drop a plane on your opponent and bomb them into submission? Isn't that much more satisfying?
In short, after forcing Double Leaf to reveal a big card in her combat arsenal, namely [Five-fold Body] + [Law Enforcers], and witnessing the seamless use of Space Magic just now, Motan had gathered all the conditions he needed.
The fact that Double Leaf excelled in Space Magic wasn't the main point. After all, for a Mage of her level, mastering Space Magic was not surprising. The key was her 'thinking' about her escape plan.
To put it simply, if Double Leaf had other more reliable backups, she wouldn't have hidden her proficiency in Space Magic from the start. Since she had been using arcane and regular five-elemental magic as a lure and deception until she instinctively used Space Magic in a fit of emotion, it proved many things.
