10 – Nico Robin
Luffy and Nico Robin first began as enemies, but after Robin saves his life in Alabasta, Luffy grows to trust her more deeply which he shows by allowing Robin to join his crew without any reluctance.
9 – Trafalgar D. Water Law
Trafalgar Law and his crew braved the Battle of Marineford and the attacks of the Marine admirals just to save Luffy.
8 – Marco the Phoenix
After Ace’s demise, he stopped Akainu from killing Luffy and urged the other Whitebeard Pirates to save Luffy, as Ace sacrificed his life for his.
7 – Emporio Ivankov / Vinsmoke Reiju
Ivankov helped save Luffy’s life with his healing hormones. He took Luffy to Level 5.5, his “Newkama Land”, and had Luffy chained to a platform as he explained his treatment: by taking away ten years from Luffy’s life, he would give him a slim chance of surviving the poison. He then injected healing hormones into Luffy, and Luffy was consumed by pain and anguish; Inazuma projected it would last for two and a half days. However, Luffy managed to successfully complete the process in 20 hours.
During their first meeting, Reiju noticed immediately that Luffy was slowly dying from the effects of consuming the Armored Stonefish’s poisonous skin. Unlike her younger brother Yonji, Reiju chose to save Luffy’s life, sucking the poison out of his body as her thanks for everything the Straw Hats had done for Sanji.
6 – Roronoa Zoro
At Thriller Bark, Zoro decided to give up his life to save Luffy from Bartholomew Kuma because he was ready to die for the dream of his captain. Kuma found this trust admirable as he was moved by Zoro’s compassion.