Webtanjiro and nezuko seem to have had peaceful lives after muzan's defeat, able to raise families.
Tanjiro, of course, did suffer massive injuries in the final battle.
Tanjiro is left blind in one eye and unable to feel his arm below the elbow, rendering his left.
Webafter a demon attack kills almost her entire family, nezuko is turned into a demon by the orchestrator of said attack, muzan kibutsuji.
At first, she is rather wild and even attacks.