You retired just like Tengen before the final battle you never expected the war to come to an end but as you were gone buried your title of a Hashira the final battle happened and you saw Sanemi and Giyu walk out alive

Everyone who had the mark was now dead the only once Hashira was you and Tengen standing this day was the anniversary of the final battle so you both were gonna visit everyone's grave which would take all day considering everyone who died

"So who do you wanna visit first?"