User blog comment:ImperiexSeed/ARCHANGEL or LEVIATHAN!/@comment-4920092-20120513234335

I think I've figured out how the age/power thing works in Supernatural.

Older members of a species are more powerful than newer members of a species, generally.

However, the age of a species doesn't necessarily make it more powerful than a younger species. After all, man had to exist before certain beasts - such as vampires, werewolves, wendigos, shapeshifters, and skinwalkers - could, yet all of them are more powerful than man.

So, while it's reasonable to assume Dick Roman is the oldest Leviathan because he's the most powerful, and it's reasonable to assume Michael is the strongest Archangel because he's the oldest, it's unreasonable to assume that Dick is stronger than Michael because he's older.

In short, a younger species can be more powerful than an older one - in this case, Archangels are more powerful than Leviathans.