Irrelevant especially because there are no anti-Christ quotes in the Quran that attempt to undermine Christ.
Thats not the only reason.
It is irrelevant the whole discussion about Christianity. Bringing Islam into the picture is absolutely irrelevant.
Its a dire need some people have to spread hatred towards other religions. Its like a sickness. And this person is obviously, absolutely ignorant. But again, it is irrelevant.
Its like two neighbours arguing over the fence. The argument is about a fence. But one neighbour says "your baby is ugly". It may hurt the other, but that's irrelevant.