Veigar's E

If I had to guess it is because it is a targeted dash. It could be a bug or unintended since he isn't played much(imo at least). You should try posting this there.

He'll pass through veigars e but then be stunned similar to sejuani's q dash. its then the veigars job to pus distances between him and xin before he can move again. this is made harder with

Xin's dash is one of many similar cases, amumu bandage, jarvens flag and drag, a couple others

We should also probably bring up what constitutes a "dash"

In my experience, Gnar Jump == dash, but an Aatrox jump doesn't seem to count. Unless lag had a hand in when it happened to me a few times. :/

Maybe it it is coded as a "blink" comparable to flash and Ezreal's E.

This happens also with leona's E, they should be more clear on what does it block or not...