"Now you see me." Jakob stated. . . before he seemingly vanished in front of everyone's eyes. . . and teleported to one side of the cyclops'es arm holding Brian. . . he used his super human strength to disarm the Cyclops and attempt to wrest Jack from the monster's grasp. . . He was not just invisible but undetectable by any mundane sense, and he could only be seen by enormously powerful magic at work. Even then it might not work unless it represented him as a barely flickering anomaly that could avoid being seen if he stood very still.