He is a famous swordsman.
The fencer showed a brilliant technique.
After harsh training, he became a swordsman.
As a swordsman, she won many tournaments.
The protagonist fought the strongest swordsman.
剣客 is a slightly literary, old-fashioned word for a swordsman similar to 剣士 but with a more dramatic, wandering-warrior nuance.
侍 refers to the historical samurai social class, whereas 剣士 focuses on skill with a sword regardless of social status.
剣士 is counted with 人, the standard counter for people, as in 三人の剣士.
Standard kanji spelling; the only written form.
Compound of 剣 (ken, 'sword') and 士 (shi, 'person of skill or profession'), literally 'sword person'. The reading is on'yomi.