is still able to use Valkyrie while stunned by 
's condem. 3 Comments
There's like a .25 second window during activation of an escape where the stun will hit, but the escape will still work. This is most commonly seen when a Tristana Rocket Jumps away from a stun (often Morg's Dark Binding). This is known and just part of the mechanic, probably a workaround so players don't get stunned while crossing walls and get stuck in the wall. The stun does work for its full duration, however, so even though the Corki moved, he could not act until the stun duration was over.
I had a similar situation to this where vayne condemned me into a wall that I was Valkyrie-ing over. I made it over, AND was stunned. Seems like I should either be stunned or make it over.