The Becoming are all warforged. The warforged started out as a synthetic race made in Creation Forges during the Last War, 400-500 years ago.
Now, they are a unified nation. They claim to be able to convert most mortals into warforged. The sales pitch is attractive: an end to age, thirst, hunger, and pain. No drugs or sex, but you won’t miss it. The rumors keep flying: If you’re tired of ordinary life and want to join with the inevitable winners, either head toward Vathirond or find a roving band of Becoming Testifiers.