He might face numerous terrifying monsters. Tartarus is full of dangerous creatures, and without his friends, Percy would have to rely solely on his own skills and the power of his demigod abilities to fight them off.
He uses his wits. Percy has always been clever, and in Tartarus, he'd use that to his advantage. He'd find ways to outsmart the monsters, like using the environment against them.
He might face extreme physical challenges like battling powerful monsters on his own. In Tartarus, there are many dangerous creatures that could be a huge threat.
His water - based powers might intensify as he is in a place filled with so much negative energy. He could learn to control the strange, dark waters in Tartarus, which are probably more powerful and unpredictable than normal water. Maybe he can use them as a shield or a weapon in ways he never thought of before.
A really cool plot could be that Percy is alone in Tartarus and he starts to lose his memory due to the dark magic there. As he forgets who he is, he still has his instincts. He begins to form an unlikely alliance with some of the less evil creatures in Tartarus in order to survive. He has to then rediscover his identity while trying to find a way out of this hellish place.
Perhaps he could make an alliance with some of the less hostile creatures in Tartarus. There might be beings who are also tired of the chaos and want to help Percy in exchange for something, like a promise to free them from Tartarus if he ever gets the chance. Percy is known for his charisma and ability to make friends, even in the most unlikely situations.
Well, one possibility could be Percy facing his inner demons. In Tartarus alone, he might have to deal with the memories of his past failures and the fear that comes with being in such a desolate place. He could encounter strange and terrifying creatures that test his combat skills and his will to survive.
In some fanfictions, Percy Jackson might be depicted as dying in Tartarus. However, this is a departure from the original series. Fanfiction writers often take creative liberties, and some may choose to create such a tragic scenario for shock value or to explore different themes like sacrifice and the finality of death in a harsh, mythological setting.
Well, one aspect to consider in this fanfiction could be the character development. Percy Jackson is already a well - established character, but as the heir of Tartarus, he might face new challenges that force him to grow in different ways. Maybe he has to deal with darker powers within himself. Another point could be the world - building. Tartarus is a very dark and dangerous place in the Percy Jackson universe, so how the author expands on that and shows its influence on Percy and the story is important. Also, the relationships with other characters would be interesting. Will his friends still trust him when they find out he has this new 'heir' status? How will his enemies react?
There's a chance that Percy meets the personification of Tartarus itself. It could be a shadowy, all - powerful being that tries to break Percy's spirit. Percy, being the brave hero he is, would have to resist and find a way to either outwit or overpower this entity in order to continue his journey in Tartarus.