One possible scenario is that Naruto is in a fight against a very strong enemy. He realizes that his normal attacks are not effective, so he taps into the black fire power. He then uses it to overpower his foe with its intense heat and destructive force.
In some fanfictions, Naruto uses the black fire in a rescue mission. The area is filled with dangerous enemies or traps. He uses the black fire to clear a path, burning away any threats in his way as he races to save his comrades.
One possible scenario is that he's on a stealth mission. Naruto might be infiltrating an enemy base, and using daggers would be quieter than his normal attacks. He could silently take out guards one by one.
One scenario could be during a large - scale battle. Naruto sees his friends getting injured left and right. He uses his medical jutsu to quickly heal their wounds and get them back into the fight. Another could be when he's on a solo mission in a remote area and he himself gets injured. His medical jutsu allows him to treat himself and continue the mission.
One possible scenario is that Naruto travels to a hidden village that specializes in sword - based ninjutsu. There, he learns their techniques and gains the ability to conjure swords. Another could be that he is cursed by an evil ninja, but as a side - effect of the curse, he can now conjure swords. He then has to learn to control this new power.
One scenario could be in a tournament. Jaden might use the Black Luster Soldier to defeat a tough opponent who has been undefeated so far.
One possible scenario is that Minato was resurrected in a wrong way in the fanfiction. His behavior after resurrection was not what Naruto expected. Maybe he was more cold - hearted or seemed to have different priorities that didn't include Naruto, so Naruto started to hate him.
One scenario could be that Naruto is poisoned during a battle. Jiraiya, with his vast knowledge of herbs and medicine, finds an antidote in time to save Naruto. Another possibility is that Naruto is trapped in a genjutsu created by a powerful enemy, and Jiraiya uses his own genjutsu - breaking skills to free Naruto.
In some fanfiction, Naruto might be wanted by everyone during a time of rebuilding. His positive attitude and ability to bring people together would be valuable. For example, after a great war, villages might want him to help in establishing peace treaties and relations. Also, if there's a mystery that only he can solve due to his unique experiences, people would be seeking his help.
One possible scenario is that Naruto accidentally bumps into Yugao during a festival in the village. He's immediately smitten and starts following her around, trying to find excuses to talk to her. Another could be that Yugao is assigned to train Naruto for a special mission. Naruto, during the training, develops a crush on her because of her cool and skilled fighting style.
Maybe in the fanfiction, the situation is more complex. Hinata is being held hostage by the Cloud in a heavily guarded location. Naruto infiltrates the place secretly. He uses his transformation jutsu to disguise himself as a Cloud ninja at first to get closer. Then, he reveals himself and uses his Sage Mode to take on all the guards. He finally rescues Hinata and they escape together.
One scenario could be when Naruto is infiltrating an enemy base. He uses his stealth to quietly take out guards one by one without alerting the others. He might use his newfound ability to suppress his chakra signature completely, allowing him to pass by detection devices unnoticed.