Since we have jutsu like Beheading and Cutter which slow you down while being cast, I thought it would be interesting if we had a jutsu which made you move faster while being cast.
Great Bubble Shark has a long cast time of 3 seconds and the projectile itself is very slow which makes this jutsu feel rather underwhelming for a lvl 35 one, there is also nothing really unique about it compared to the Water Shark other than the fact that it can snare enemies that it hits.
I think an interesting way to make this jutsu more unique and usable would be to make the user move faster while the jutsu is being casted. The animation of this would be the user riding on top of a shark fin or some sort of a wave. It would open up interesting plays like being able to ride the shark to evade a jutsu or to chase down an opponent with it.
How the animation while casting the jutsu could look: