If he's running away with q, then he's not useful. If he's running towards you with q, then he's visible. I fail to see how it's broken.
Truly broken spells are rare, like on release Grave's Q (literally oneshotting enemy adc) or Lux's planned W (which was the same projectile, it just made herself and allies hit invisible. Thankfully that shit was changed before she was released, praise on to Morello, in his infinite wisdom) or Eve's old 30 second invis that ended when she auto'd somebody, stunning them, or old Pantheon's E doing 2000 damage aoe with 2 items.