User blog comment:Willbachbakal/(Champion Rework) Evelynn, the Widowmaker/@comment-1920550-20150916230152/@comment-1330314-20150917030047

The idea behind W is that using it at night would instantly place you back in perma-stealth instead of requiring you to not do anything for ~3 seconds. The ult isn't a stasis effect, rather, it basically isolates Evelynn and her target completely from everyone else and forces a duel between the two.