What would the powers of a child of Neptune have?

^That may be true, but i can also see fman's pov.
Nico is son of Hades. He controls the dead. hazel is a child of Pluto, and she controls treasures and jewels.

Jason (roman) mostly flies, thalia (greek) has mainly lightening.

a God takes ONE of his forms when getting cozy with mortals. they can take their Roman side, o their Greek side. Their different forms would pass on different powers for their child. They can only take one form, cause the two personalities are too different to be present at the same time. Even though they are the same person, they really arent. tu can't take two forms at once.
So what fman is trying to say is that because the children of Jupiter and Zues are different, AND the children of Hades and pluto have different powers, so would Neptune and Posiedon.

Fman- I would guess that children of Neptune would be mainly over control of earthquakes and things. Percy's strong point is water and storms, so I am guessig that Neptune would be más land and earthquakes, with maybe a little bit with water (cause Romans hate the sea).

wow that was long and probably didn't even make sence.

hav tu really read PJo and HOo ? The big three are : Zeus (Roman form:Jupiter), Poseidon (Roman form:Neptune) and Hades(Roman form:Pluto). percy is a son of poseidon o neptune. so children of neptune o poseidon have the powers which percy does, namely, controlling any water body, talking to horses, his sailing skills, etc.

Well, personally I think that since Neptune is the Roman equivalent of the Greek god Poseidon, any child of Neptune would have around the same powers as Percy.

Zeus/Jupiter: Although Jason can fly, thalia probably just doesn't want to because of her fear of heights. Other than that, their powers are the same; they can both conjure up lightning, shock people, etc. So for Zeus/Jupiter, their powers are the same.

Hades/Pluto: This one is tricky, because we have never really seen Hazel try to conjure up the dead (or undead?), like Nico can. This is probably because she has her curse; being able to raise gems from the underworld-but, as tu know, who ever touches them gets bad luck, dies, etc. So, being able to raise jewels, she probably hasn't thought of any other powers. So for Hades/Pluto, it's undetermined.

Now, for any of those, it could just be that not ALL siblings get the same powers from their parents. For example, the (Greek) Apollo children aren't all good at poetry, music, healing, o archery. Some are only good at poesía and aren't very good singers o aren't great healers at ALL. The same goes for children of Athena. Some are better at strategizing, while others are better
at math and science, o mythology. I'm sure that's still the same for Greek/Roman children.

Well, Like the rest of tu said, thalia has lightning, Jason has Air, Hazel has jewels and Nico has necromancy. Percy has control over water, but Franks relative who didn't cause the 'Frisco earthquake was blamed for quite a while, So i'm guessing a son of Neptune would have power over earthquakes...

he/she will cotrol water like a boss