Ninja Lag

The warping of time and space so that a real event happens after it theoretically should

an example of ninja lag, in anime is when swordsmen or ninja slash their swords at each other, sometimes they have time to put their sword back into the sheath and walk away before the other person is actually cut by the blade.

Lag Ninja

Video game opponent who appears to teleport all over the map due to lag.
Sometimes using a lag switch.

"Dude I can't fucking hit him! He's a fucking lag ninja!"