Percy would win and its not even close in my opinion. His morals would help him destroy any foe, Including that of Ares, Kronos, And many others. Percy is a better fighter, A better person, And a better character. As a fan of both trilogies, I can indeed say Percy would win.
Percy Jackson was able to beat Ares ARES for crying out loud the god of war at his own game and for the record Percy was offer the chance to become a god he is the son of Poseidon god of the sea earthshaker and was able to one pop two pop bam Typhoon which defeated Zeus Harry start quaking in your spells because Percy Jackson is coming
Percy Jackson could kill Typhon in 3 seconds. Like, Totally yeah. Boo. Yah. GO PERCY JACKSON! Woo-hoo! Who is the best? He's awesome! Ah hoo! All right! Who let the dogs out. So yeah. Who could beat Percy Jackson? No one! Percy Jackson is the best! Percy Jackson- oh. BYE!
All you have to do is have some prep time. Percy is water based so you need to dehydrate him and keep him from water. Second he is not even a major God just the child of one so he will not be OP.
Harry just has to make him mute and remove the water from his lungs and blind him or do so gravity spell. Sure he is fast but harry is a clever mortal and the greek gods are all a joke.
I think that harry potter would win because he could just do the avada kavada curse and win. Even though percy jackson can relive in water he would die before that. So I think that harry potter would crush percy jackson in a really cool battle. The battle would be awesome.
Since harry potter has dementors. Dementors can just suck your soul and now your life is pointless, And worse than being dead. Percy Jackson, Sure he can reheal in water. But the killing curse strikes you right away and now your lying on the ground not breathing. That's why Harry Potter is better than percy jackson.