The wording on Hysilens’ ultimate is a bit confusing at first, but it seems like she deals DoT for each detonated DoT, up to eight times.

But with a setup like Hysilens + BS/JQ + Kafka (with Tutorial) + one Break DoT, that only adds up to seven.
So either they’ve balanced her around Kafka’s S1, or there’s another DoT source coming soon lmao