Well, Your theme is "soul" oriented... so that has to be a sticking point... but your role doesn't seem to be specific... You need to have a direction in mind before you jump into making a champion. Four instance do you want this champ to be a jungler? that kind of fits with your W ability... but your W ability also doesn't seem to be that effective or purposeful except for in a possible escape situation. So that's an issue with what you have currently. An even bigger issue is your Q, Riot does not want you to be able to deny farm from your opponent by killing your own minions. Also your Q sounds close to Malzahar's DOT ability, only yours doesn't jump and your doesn't specify if you can target enemy champions.
Consider a few things that will make it easier to make skills...
What are the characteristics of Souls?
EX. Life, death, fear, emotions, etc
Are there ways to implement them that wont break the game?
EX. taking control of an enemy champion would possibly be unbalanced
What is your characters back story? Does it possibly play into the roll?
Your concept is not so much unfinished, as it's still in it's infancy, I'd be glad to offer creative help if you'd like, add me in game and when you see me online shoot me a message and we can talk further. I'm not going to say i am the best, but i don't mind trying to help show you the process i go through.
