Archer is unmistakable. He has white hair and generally wears black armor and a red cloak. The fool has no pride and as such, his ability enables him to make fakes of other weapons. You could say he can do the same as I except with counterfeits instead of real weapons.

Saber is my wife here in Mayfield and she will be no problem for you. Out of all the servants, she has the most honor and will not attack you unless you force her to. Regardless, aside from myself, she is the strongest servant. Lancer has too much pride to put him into contention but Archer is a very dangerous fool indeed.