Resha wasn't aware of the entire truth, but thanks to Orakha's multiple revivals, some of the information about the Supreme Tusk in the Transcendent Eater was revealed. Raaha learnt about it from Orakha and then informed Resha.
It was through this that Resha knew about the Supreme Tusk Gannala's plans regarding her seven children, the goal of which was to kill the Boar King and reach the Mystic Grade.
When one of the seven has a child, the path to the Mystic Grade in them is transferred to the child. But if the child isn't an Empyrean Tusk, then the path is lost forever.
After all, it acts like a bridge between the seven and their respective children, accumulating the countless variables they create to forge a path to the Mystic Grade.
Resha stared at the cup before him. It was four times larger than his head and instinctively upon perceiving it, he was able to conclude that the cup had a volume of 27 litres. Currently, it was empty.