One possible fanfiction could be that Naruto, while on one of his missions in a strange new dimension, stumbles upon Freddy Krueger's glove. Naruto, being the curious ninja he is, might first be cautious. He would likely study the glove, trying to figure out its power. Maybe he'd sense some dark chakra within it. He could then decide to take it with him, thinking it could be a useful weapon against his enemies, but little does he know the nightmares that could come with it.
One possible plot could be that Naruto stumbles upon the glove during one of his missions in a strange, other - dimensional realm. He might initially be curious about it, not knowing its true power and the evil associated with it. As he investigates, he starts to have strange nightmares similar to those Freddy Krueger induces, and he has to figure out how to stop the glove's influence using his ninja skills and chakra.
Naruto could try to incorporate the glove into his fighting style. He might think that the glove's ability to attack in dreams could be a useful addition to his ninja techniques. For example, he could use it to enter an enemy's mind during a battle and defeat them from within their own nightmares.
Naruto would probably be initially shocked. He's used to his own world's kind of energy, like chakra. But he's also a curious guy. So, he might try to figure out what this dark energy is all about. He'd likely be cautious though, because he can sense it's not good.
He could fall in love with a fellow dream entity. Maybe there's a beautiful and mysterious being in the dream world who catches his eye. This being could be like him, having some power over dreams, and they start to bond over their shared abilities.
Freddy Krueger's story goes like this. He was a child murderer who was burned alive by the parents of his victims. Now, as a supernatural entity, he seeks revenge by entering people's dreams and causing their deaths.