[GAMEPLAY] Qiyana's ult "freezes" Sett's animation

When Qiyana and Sett ult each other, Sett's animation can bug out. This can only be caused if Sett ults right before the river stun on Qiyana's ult goes off. (Not the main wall stun.) Summoning Rift Herald as Sett will cause him to go into airplane mode, where he looks like a little bug on the ground. His animation is stalled until he gets regular Qiyanna ulted again.

Steps to reproduce:

1. Ult Sett with Qiyana so that the Qiyana ult has river buff, but not into a wall
2. Walk towards Sett as Qiyana
3. Ult Qiyana with Sett between the knockback and the river stun near the end of the window. (It seems to work better closer to the stun.)

At this point, Sett's animation should freeze. For an extra step: 4) Cast rift herald as frozen Sett.

Things that need to be tested: Sett ulting another character instead of Qiyana to start animation freeze. What causes Sett's animation to go back.