There are several potential drawbacks. Firstly, using blood control might be physically draining for Naruto. Since blood is such an essential part of the body, constantly manipulating it, whether his own or others', could take a toll on his own physical energy. Secondly, in the Naruto universe, there are many different types of blood, and some might be resistant to his control. For example, if an enemy has a kekkei genkai that affects their blood in a certain way, Naruto might find it difficult to control that blood. Thirdly, the public perception of his new ability could be negative. People might fear him because of this rather unusual and somewhat macabre power.
A possible drawback is that it might require a great deal of concentration. Naruto is already dealing with a lot in combat, like using his various jutsu and strategizing. Adding blood control to the mix might overtax his mental resources, making him vulnerable to attacks. Also, if his enemies figure out his new ability, they could try to counter it by using techniques that disrupt blood - related manipulation, like creating strong chakra fields around their bodies to prevent him from accessing their blood.
One potential drawback could be the moral implications. Controlling someone else's blood is a very invasive and potentially cruel ability. Naruto, who is known for his kind heart, might struggle with using such a power. Also, it might be difficult to control precisely, and he could accidentally harm allies if he's not careful.
The drawbacks could be significant. He may start to isolate himself because he knows things that others don't. This could lead to a breakdown in his relationships. And if the wrong people found out about his ability, they would surely try to use it for their own evil purposes. He would constantly have to be on guard against that. Another issue is that the future he sees might not be set in stone. If he made decisions based on what he saw, but then the future changed, it could lead to chaos.
One implication is the moral dilemma. Percy would have to decide when and how to use such a powerful and invasive ability.
He might also face moral dilemmas. For instance, using this power to heal someone might seem noble, but if he uses it to harm or manipulate others, it would be a different story. He has to constantly struggle with the right way to use this power.
One implication could be a change in his combat abilities. He could use metal objects as weapons or shields more effectively. For instance, he could make a sword fly towards his enemies or create a metal barrier to protect himself.
One advantage is better defense. He can quickly grow thick bushes or tall trees to shield himself or his allies from attacks. For example, in a battle against powerful ninjas, he can create a forest around them for protection.
It could also have implications for the Hulk himself. Usually, the Hulk is a wild and uncontrollable force. But with Naruto in control, he might be able to be used in more positive ways. The Hulk could be directed to help rebuild instead of just destroy. And from a character development perspective, the Hulk might learn to control his rage better under Naruto's influence, and Naruto might learn new things about power and responsibility from having to control such a powerful being.
One drawback could be that it might disrupt the balance of powers in the Naruto world. Naruto was already a powerful ninja, and adding Sans' powers could make him overpowered compared to others, which might make the story less interesting as there would be less of a challenge for him.
Well, the main drawback is the damage to his body. The Eight Gates technique is very taxing on the body. Naruto could end up with permanent damage if he uses it too often. Also, it might change his personality. The intense power of the Eight Gates might make him more aggressive, which could be a problem when dealing with his friends and allies. And from a strategic point of view, if he uses it too early in a fight, he could exhaust himself and be vulnerable to counter - attacks.
One drawback is privacy concerns. Since personal assistants collect a lot of data about you, there is a risk that this data could be misused or leaked. For example, your voice commands and the information you ask for could potentially be accessed by unauthorized parties.