Sirius

Sirius (シリウス, Siriusu) is a former bodyguard to Saint Basil and the current engineer of The Dream Pirates. Sirius first encountered the crew after the Dreams attempted to retaliate against the Celestial Dragons. After being defeated by Knave Dhahaka, and Saint Basil's house destroyed, Sirius wandered for several months before joining the crew on Mercuia's request.

Devil Fruit
For more information, please see: Yami Yami no Mi