I wonder where people are getting these Muzan is too op vibe. After all demon powers I've seen so far, his is not really that much above the others in his own group, maybe because he is weakened I don't know, but I can actually see the combination of Tanjiro and Giyu pulling off a victory out of this one. Tanjiro is literally unreadable an can see everything in slow motion when he is using the sun style, Giyu can move in superhuman speeds, both of which can serve as a counter for what we've just seen from Muzan in this chapter. Moreover, Tanjiro still has the 13th move to learn from his Fire god technique, along with Giyu's clusive water move, he could also possibly learn, both of which may allow him to fully revive the Sun style and give him the power up needed to finish Muzan up.