Lucian Dash Bug
I believe Lucians 
Dash (E) ability gives him frames of invincibility, I've witnessed it a few times and this seems to be the most obvious display of the bug: https://www.youtube.com/watch?v=4LT9nsFPCpk
I believe Lucians Dash (E) ability gives him frames of invincibility, I've witnessed it a few times and this seems to be the most obvious display of the bug: https://www.youtube.com/watch?v=4LT9nsFPCpk