The First Descendant

This is will unlock automatically by completing one of the first sub-quests you receive to unlock your second Descendant, Bunny. Unlocking her is a research task which counts toward this achievement. Speak to Anais in Albion to begin research tasks. Looking at any of the tasks will show the required materials, and hovering over a material and pressing  will show which activity you can obtain it from. Once you have all the materials and enough gold, begin the research task. Bunny only takes one minute, but most will take hours (with the option to speed them up using resources). You'll get all the materials you need for Bunny from the main story quests.