Eustass Kid has already shown his abilities, wich is something related to magnetism, even though many people believe he can manipulate electromagnetism. If he could, he probably as a LOT of potential, having one of the strongest Devil Fruits around there.
I believe he can manipulate electromagnetism.
Electromagnetism Power Possibilities:
1.Electromagnetic or magnetic blasts
2.Mind control (probably only the weak ones)
3.Controlling all of the electromagnetic\magnetic objects around him
6.Radiation manipulation (limited)
7.Electricity manipulation (limited)
9.Density manipulation (limited)
It’s just really REALLY strong. The possibilities are INSANE, I think some of these are possible, some are not that possible, but all are possibilities for this overpowered Devil Fruit.
He has a lot more possibilities than that, but these are the most impressive to me.
He could probably even push someones body like Pain by controlling the metallic parts of our body, and our electromagnetic fields.
And LET’S NOT FORGET that all Islands have a strong magnetic field in One Piece, so, not only he probably can sense them like a log pose.
And he can probably cause earthquakes by disrupting the electromagnetic fields of the islands, causing the ground to vibrate and ,possibly, destroy, but of course different from Gura’s power and limited to the ground.
Not only that, he should be able to use a strong Armament Haki and Observation Haki.
He definitely has lots of potential to be a top tier in a future.
Theory by Eustass D. Shanks