Jhin doesn't blink on his login screen.

Blinking only messes with your aim.

Hes cool like that

It's because of all the mobility creep in the game.

http://24.media.tumblr.com/tumblr_m3wpy824kf1rrg3dvo1_500.gif

Also it's a psychopathic trait to blink less than normal.

Behind every mask

is another mask.

Especially in cinema, psychopaths rarely blink on film. That creepiness really helps sell the role. Any disorder even remotely linked to schyzophrenia typically has this trait on some level.