At first, because of this, they didn't attack at all. For the first five years after Dyon nearly killed all of their young geniuses, they didn't send anyone. In all likelihood, they were attempting to contact, or, rather, hoping to contact their backers for a helpful solution.
However, one had to know that the elusive backers of the 99 universes had been in control of them for several million years, from the destruction of Soul Rend Peak, to now. With so much time having passed, several generations would have come and gone. Over time, their interest in the usefulness of the 99 universes would have plummeted.
As expected, those backers hadn't contacted the 99 universes in numerous years already, closing in on more than a hundred thousand by now. And, even before that, the time lag between contacts had been growing. In the end, the 99 universes would only rely on themselves.