Possible Sion bug with Rift Herald?
I was pretty sure Rift Herald was the same as Dragon/Baron, immune to all forms of CC.
In the two games I played tonight, the Rift Herald WAS immune to my Q knockup on Sion, but my E would still send the Herald flying like any other monster. It's not supposed to work like that, is it?
I know Dragon is still immune to the E knockback.