Lesser Demigods
Heralds perhaps.
These entities are player characters like Demigods, but of inferior stature. Some are servants of the Demigods themselves, some are simply exceptional individuals seeking ascension.
I could see each having access to maybe at most 4 abilities in a skill tree ala a normal Demigod, but their overall character power would at most be 60% to 75% of a true contender.
My notion was related to play in single-player campaigns. Perhaps a certain scenario pits the player`s Demigod against two of The Oak`s (for example) lieutenant`s, his Heralds, who fully cooperate with each other in order to protect their master lord. They would be weaker apart, but then again there are two of them acting in concert to defeat the player in that scenario.
Further, as I pondered this, it occurred to me that such could be an interesting handicap challenge for multiplayer. Players could endeavour to be gutsy enough to choose from a field of Heralds instead of from the superior Demigod ranks. Could be neat.