[spoiler] Doubtlessly Truth did win at the end like always.
Death Note is a series that supposedly justified the unjustifiable in the process of justification. It was bohemian. the bohemianism though breaks away from the accepted, could be witnessed returning to the same recognition. Light was the creator of a New World where there's no criminals so that justice reigns. But in making the New World where God becomes the only one to punish, it makes the God himself the criminal. Near was right about Kira being nothing but a serial killer who's responsible for a mass killing in the history. Kira's end-aim to be a God of the New world, taints his character with humanity, callousness and mercenary motives. So at the end, Kira is punished and L,after all, becomes Justice. In the absence of Kira; the killer, who's going to take care of the rest of the criminals? Well, that we call reality of life; 'anyone after death neither goes to hell nor heaven', 'no one belongs to either justice or injustice.' Humanity is about both. Reality cannot be completely varied or 'deleted'. everyone will eventually die. What's important is the fact that, Truth never Fails.