..for that day shall not come,
except there come a falling away first,
and that man of sin be revealed,
the son of perdition;
2 Thessalonians 2:3
Antichrist .... -OR- .... Vicar of Christ?
...from Late Latin antichristus, from Greek antikhristos [I John ii:18], from anti- "against" (see anti-) + khristos (see Christ).
....from Anglo-French vicare, Old French vicaire "deputy, second in command," also in the ecclesiastical sense (12c.), from Latin vicarius "a substitute, deputy, proxy," noun use of adjective vicarius "substituted, delegated," from vicis "change, interchange, succession; a place, position" (see vicarious). The original notion is of "earthly representative of God or Christ;"
Online Etymology Dictionary