Even A Little Increase Can Make a Big Difference
As the two Beasts exchanged multiple water-based attacks, Ban was also slowly crept towards the side of the river. Yakob and Rila were also behind his back, hiding behind the bushes to not alert the two Beasts.
For Yakob, this was the best case scenario. As long as the Frog and the Crab duke it out and doesn't notice Ban getting closer to the Pure River Water, his job will become much easier. He won't need to fight with the crab or the frog to garner their attention and Ban will be able to get the Pure River Water without any problem.