Janius didn't bet on Zharanthixil being calmed by his words. In fact, it made it worse. When he stepped towards Janius, Janius took one step back only. He couldn't give more ground into the deeper water where he would have an advantage.

"Wait-!" When the Master-Hunter lunged, Janius tried to deflect him rather than strike. Despite his best efforts, Zharanthixil sent them both barreling into the shallow water of the river. Janius had trouble focussing with the water everywhere. He tried his best to deflect the the Master-Hunter's strikes and prevent himself being pinned under the water, but it was a losing battle for him. Janius couldn't say whether he was stronger than Zharanthixil, but from his position, he couldn't land any strikes if he wanted to.

In a panic, he tried to call upon his beast spirit. It was there, but didn't want to come out yet. He prayed that Zharanthixil would stop short of murdering him so he wouldn't have to persist in calling it.