Can someone outline what an evil path looks like from a storytelling perspective?
It's a matter of motivations and end goals.
"Good" path is one of altruism. You're doing it to help others, the end goal is to make the world a better place for citizens.
"Neutral" path is one of pragmatism. It would generally be a good idea to stop tyrants, psychopaths and world ending disasters.
"Evil" path is one of egotism. You want to make things better for yourself. More power, more wealth, more influence.
Now say you're evil. I guess you still get a call to action of some sort. You still have to face challenges along the way. But the challenges presented in the story are evil, by nature. So this becomes a story of evil overcoming evil? Or is your challenge to join the evil?
It's not necessarily that the challenges are evil, but how you choose to approach them are evil. More "Kill now, ask questions later" or deceiving/coercing people to further your agenda.
As far as overcoming evil/joining the evil... That depends on the specific story. The general idea is there's something you wish to gain and Evil McEvilface is likely doing something that will result in their power being increased and you want to take it.
A good example of this in BG3 is Astarion's story. Cazador is Mr Evil McEvilface and he is on a plan to Ascend to gain power. Astarion can thwart him and gain that power himself. The end result is still that the big Evil is gone, just as in a "Good" path, but the difference of gaining the power in an evil path vs the power being removed completely in a good path.
I mean, what exactly are people wanting to happen? What is it that you picture your character doing that your character can't do?
It would be things like, working together with the Absolute more. With more content where you get to flex being a True Soul.
Perhaps you can convince Balthazaar to help you overthrow Ketheric.
Given that the game sets up animosity between Ketheric, Gortash and Orin there could be content where you ally with one of them to dispose of the other 2, or have a situation where you simply dispose of 1 and then jointly control the Netherbrain, or have situation where you systematically betray all 3 of them.
