So after doing a bit of research i’ve realized that we might not see a left handed swordsman part of the demon slayer corps because of one main reason

Swordsman in Japan (especially those who used katana) were always taught to use they’re right hand no matter if they were left handed

i’ve seen a couple reasons why like mostly everyone was right handed and kept things easier to so that when they were walking or in group they’re shafts wouldn’t clash there was also one saying that they never wanted to expose their hearts

all in all if demon slayer follows traditional japanese culture then we most likely won’t see a left handed swordsman part of the demon slayer corps

TLDR: bcs of japanese culture most likely no lefty swordsman in demon slayer :(