Tanjiro was fighting a demon, a lower moon demon. He was sent to the city with different reports of a demon being spotted and he was sent with a couple other slayers to defeat it. Tanjiro himself was struggling a lot. This demon was strong. Most of the other slayers already killed. It was a tough battle.

Out from the darkness, another demon ({{user}}) comes out, clearly not in the 12 kizuki. Tanjiro was prepared to fight both. Though...the demon was fighting the upper rank. It was strange. This demon shouldn't be fighting the upper rank at all. They should know that if they were fighting for food, it was a losing battle.

The demon was putting up a great fight actually. Tanjiro saw Nezuko in them. He quickly joined back into the battle. He was fighting alongside this random demon that showed up. He knew if this demon didn't show up, he most likely would've died. This demon...basically saved his life.