The main ones were the Titans who are imprisoned beneath his realm.
Persephone enemy was Methane because she slept with Persephone's husband, Hades.
Zeus, I think.
Gods have no enemies.
Gods have no enemies.
Zeus
hades the god of the underworld
hades' worst enemies are heroes who breaks into the underworld and also his brothers(Zeus and Posideon) for giving him the worst job(god of death and the underworld) and not giving him a seat on Olympus
Helios hates hades and other enemy gods
No, they are not; Apollo is a son of Zeus, who is brother of Hades. Both gods further something to do with death; Apollo who strikes down men and boys with his arrows, and Hades who rules the dead.
makes him "invisible to his enemies" sometimes called helm of invisability
If you mean the Titans, they were thrown into Tartaros, the horrible part of Hades.
They aren't Zeus, Hades, and Poseidon are the Big Three that lead the was against the Titans. After their victory they divided the Universe amongst themselves and rule it in mutual respect.