From a power - development perspective, it could open up new storylines. He might need to train to control this power better, and this could lead to interactions with other characters who can help him. Maybe he has to visit a healer or an old sage who knows about such powers. Also, it could create new alliances or enemies. Those who fear his power might try to stop him, while those who see potential in it could team up with him.
Socially, it might make other characters view him differently. Some might be in awe of his new power, while others might be afraid. It could also lead to moral dilemmas. For instance, should he use this power on humans or only on monsters? Using it on humans could be seen as a violation of their rights and natural order.
One implication could be in combat. He could potentially use the blood of his enemies against them. For example, if an opponent is bleeding, he could make the blood blind them or make their movements sluggish by interfering with the normal blood flow.
One implication could be in the area of healing. If Percy can control blood, he could potentially direct it to areas of the body that need repair. For example, if someone has a cut, he could make the blood clot faster by controlling its flow and the platelets within it. This would make him a very valuable asset in any medical emergency within the world of the fanfiction.
One implication is a change in his abilities. Elves are often associated with things like archery and nature magic, so Percy might gain these skills. His physical appearance would also change, probably getting pointed ears.
One implication could be that his relationships with other characters change. For example, his friends might be initially scared or cautious around him. His lycan abilities would also mean he has new powers to use in fights.
One consequence could be that Percy gains a lot more respect among the demigod community. Controlling Typhon is no small feat, so he'd be seen as an even greater hero. Others might look up to him more and he could potentially become a leader in a more significant way.
Well, it could mean a huge power boost for Percy. Hyperion is a powerful Titan, so Percy might gain abilities like enhanced strength, maybe some new control over light or the sun. It could also change his status among the demigods, making him even more of a force to be reckoned with.
Well, it would completely change the dynamic of the 'Percy Jackson' universe. Artemis is a powerful and independent goddess, and this would shatter her image as a virgin goddess. For Percy, it would put him in a very strange and controversial position. Also, it would likely cause a huge upheaval in the relationships between the gods and demigods.
Well, in some fanfictions, it might be related to his demigod powers. Since he has a connection to the water element, blood being a liquid could potentially be manipulated in a way similar to how he controls water. Maybe he can sense the water content in blood and use his will to move or influence it.
One implication is the moral dilemma. Percy would have to decide when and how to use such a powerful and invasive ability.
One scenario could be Percy using his ice - controlling powers to save his friends from a giant ice monster. He freezes the monster's legs, immobilizing it long enough for them to escape.
It would be very shocking. Percy is a beloved character, and such a fanfiction would be a huge departure from the normal, positive portrayals. It could have a negative impact on younger fans who look up to Percy as a hero.