Casting spell Steal during Strafe causes Rubick to lose a Strafe charge Rubick
's Spell Steal
creates a projectile which flies from the target to Rubick. This projectile is normally not disjointable. But Strafe can disjoint it, and wastes a charge to it. This means when Rubick uses Spell Steal while having Strafe active, he will lose a Strafe charge for nothing.