The answer to this question is Yama. There are a lot of things that Yama is known for but one of the very first descriptions is that he is the first man who died. Yama is said to guard the gates of hell and he also watches over the dead.
From the description, you may think that he is someone who is bad but he will not be a Hindu god for nothing. He is known to be wise and he would do everything in order to maintain the harmony of the place that he is watching over. He is considered to be an ancient being especially since he is one of the Vedic legends.