FWIW I think the parent comment is incorrect (unless I misunderstood it, of course); I responded in more detail here [0] but the tl;dr is that the Bible does describe the (big-a or little-a) "antichrist" as more-or-less entirely opposed to Christ. (Not to mention that Jesus himself warned about copycat "Christs", in Matthew 24:23–27, and calls them "false" and says that they "deceive".)
[0] https://news.ycombinator.com/item?id=50243942