In fiction, the swordsman is a standard trope, which is understandable. Afterall, Heroes Prefer Swords
and Katanas Are Just Better
. Unfortunately, in a modern or future setting, this would seem odd, as swordsmen would be heavily obsolete. Likewise in a setting in the distant past, before the advent of the sword.
That's where the Anachronistic Swordsman
The swordsman may be a regular guy in the modern world who just happens to fight with a sword, a sci fi vagrant with a high tech laser blade or a warrior of justice who fights evil warlocks with a magical sword. Basically, a swordsman in a setting where there shouldn't be swordsmen.
Subtrope of No Such Thing As A Deprecated Weapon
(note: still in YKTTW
) and Heroes Prefer Swords