He won't look like the devil. He will probably show up as Jesus or something. That's why people will believe it's not him, but God will know what they believe in their hearts.
Satan, the devil, the anti-Christ, whatever, can't fool God, but he will try to fool us.
Lot's of Y's out there. The devil takes good things and makes them bad, even the peace sign.
"However, to my chagrin, I found that this same symbol has a very dark past, much older than that. It was used by Hitler's 3rd Panzer Division from 1941 - 1945 on their regimental badge, seen to the left. Many Soviet, Polish & Hungarian people, having suffered atrocities under the Nazis, must certainly have struggled with it's use as a way to communicate peace. The symbol can be found on the tombstones of many of Hitler's SS troops also.
There are numerous associations with Satanism & as a symbol of a 'broken Jew' or 'broken cross' from as early as the first century A.D. The Emperor Nero, who despised Christians, crucified the Apostle Peter on a cross head downward. Today, heavy metal lyrics & imagery use it to communicate anti-Christian sentiments. It has been used to support communism & the 'anti-God' movement for many years. The founder of the Church of Satan depicted it on the backdrop for his altar."
http://jaspersgems.blogspot.com/2011/11/
https://en.wikipedia.org/wiki/Saint_Peter
https://en.wikipedia.org/wiki/Pallium