Prestige
At Rank 100, you can Prestige your Bloodline. This will award you a new Prestige level, which includes a badge displayed on your Bloodline screen. It will also give you an additional reward, such as Bonus XP, additional starting Hunt Dollars, a Legendary Hunter, or a Legendary Item on certain Prestige levels.
Prestiging will, however, reset your Bloodline back to Rank 1. Hunters, Equipment, and any excess Hunt Dollars over the amount of 8,000 will be lost.
Legendary unlocks, Blood Bonds, and Book Mastery progress will be retained and are never lost through Prestiging.