[Endoperez]

Luck affects the change of heroes. You won't get any heroes with Misfortune 3. Anything above that, and you have a small chance of getting any one of your nation's heroes. If you can get heroes, you can get all of your nation's heroes.

Different nations have different heroes. Their power and usefulness can change a lot. However, some nations have one powerful and several weaker heroes, or vice versa.

There was a DomII list of heroes, but I doubt anyone has compiled one for Dom3. I doubt all Dom3 heroes have been seen yet.

Some examples of very good heroes:

Tien Chi has immortal heroes (If they die in your dominion, they are reborn in your capital instead of dying. They also heal their own afflictions with time). IIRC, one is a mage (althuogh he suffers from a curse), another is a healer who can heal afflictions of other units as Arcoscephale Priestesses, third is a skilled warrior.

At least EA Niefelheim and MA Jotunheim have Angerboda the Great Hag. She is a giantess with Nature 3, Astral 2, Death 3, Blood 2 IIRC.

Some examples of common heroes that won't win a game for you on their own:
Spornsjarl of MA Jotunheim. Jotunheim has Giants. They also have Vaetti. They are tiny goblins. They aren't that useful compared to the Jotun giants. Spornsjarl is a vaetti. He is a great chief among Vaetti. He wants to prove to the big folk what his kind is capable of! Unfortunately, he's a fragile commander with a Standard effect. He can lead a stealthy Vaetti force to enemy lands and his Standard ability keeps them fighting longer, but he often dies if you try this.

Niklatu the Lizard Hero. C'tis, I'm not sure of the ages. He is a very handsome lizard. He is a great hero and adventurer who has e.g. saved the most sacred of the Hierodules from a corrupted Sauromancer. He wears some minor magical items, Rainbow Armor at least, and is a capable C'tissian commander without special abilities.