You think it's unfair? Ha! If there truly were absolute fairness in this world, then the dozen people you killed shouldn't have died. Instead, when you made your move, they should have successfully countered and rid the world of a menace like you!
Your biggest mistake is your lack of self-awareness.
As a young cultivator, knowing you have no talent, no background, no extraordinary luck, you should set aside your delusions and diligently do every little thing, accumulate virtue and forge good karma.
But you were greedy, wanting to ascend to the heavens in one step, so you fell to the evil path.
If you had self-awareness, you would know that a small ant from the righteous path, once fallen to the evil path, remains a small ant among evil cultivators.
