Ignatius is watching for when it happens, but when it does, he doesn't actually raise a hand to defend himself. Instead, he lets Rita hit him with the full force of her spell - he disappears with the water as it crests down the hall, gradually dying out as it travels around a corner.

Ignatius is gone with it, but... You know by now he almost certainly isn't actually gone. He looked like he was smirking as the tidal wave came upon him.

On the bright side, Herbert and the floor are no longer on fire.