When I get involved in something my focus is obsessive. I focus on my garden, or I focus on my writing, and forget completely that there may be other things requiring my attention.
So in a sense that's the way my characters come out in the first draft. Focused on getting through the story, getting to their HEA (or whatever) they forget all the other little things that make up their lives. Taking care of children, livestock, learning magic all become secondary. But a well rounded character is more than just a single-minded focus on survival. Even in an immediate emergency (such as an earthquake) people are going to be thinking about other things--watching their grandmother's vase shatter, wondering if the dogs are safe, curved protectively over children. In the heat of the moment these might just be momentary distractions, a fraction of a second in the play, but they are still there.
One-dimensional characters aren't fun to read. They may create a contrast, but they are generally not POV material.
Do you remember when you were growing up, the old man who always yelled at everybody to stay off his lawn? He appeared for maybe thirty seconds, threatened to call the police, and disappeared again. No real interaction, no reason for what he does. He's a one-dimensional character. Now what if that man has a little yappy dog? Does that add character? What if he never keeps up the yard so his "lawn" is all tall weeds?
One little detail at a time, he becomes a true character. Still not enough, though. These are details that are perceived from outside. Right now he's focused entirely on one thing--keeping those darn kids out of his yard.
We need more to make him into a fully rounded character. If his only purpose in the book is to yell and scare the kids, that's fine, but we still need to see him as a real person rather than a cardboard cutout.
Chinish peered through the crack in the curtains, waiting. The animals were playing in the street, kicking their ridiculous toys around. A little further. Just a little further. One darted after the ball, trying to catch it before it flipped past the end of the wall and into his yard.
The ball rebounded from the curb and skittered along the low wall to where his property dipped down below street level.
He sucked in a breath in anticipation of the feast.
The ball bounded through the gap. The animal hesitated, looking back at its companions, then gingerly made its way down into the yard. Chinish struck as soon as the child was within range, an arrow into the soul that sucked, sucked, sucked, pulling all that energetic power. This one had more power than most, and a new thought occurred to Chinish. His eyes widened
The child started, turned toward the house instinctively for a moment, its eyes frozen wide. When no one appeared in the doorway it worked its way through weeds to where the ball had come to rest and Chinish threw the door open. "Get out of my yard, you filthy animal!" The child was close now, close enough to see the patterns in the wide eyes. So close that the flow between them was visible.
The child's fear was sweet, increasing the flow of power. Chinish sucked it all down, careful not to reach too far or take too much. Oh, sweet. Like a draught of cold spring water after a long walk in the desert. It filled him, chilling him from the inside out until he thought he might shatter.
The child stood, terrified, then grabbed its ball and scurried through the weeds to the street.
Chinish kept the contact, let the power soak into him. He felt the child's exhaustion, heard through the link the complaint of a headache. I'm going home.
Chinish smiled and kept the contact. Tonight, after all memory of the incident had passed, the child would die peacefully in his sleep. Chinish had never emptied one completely before, fearing repercussions from those who might be able to sense his interference on this plane. But maybe, just perhaps the surge of power as the soul left the body would be enough to open the portal again, to send him home.