A preview of the Cover of One Piece Volume 102 has just been revealed with some interesting details.
The new cover shows Sanji having blue flame for his Ifrit Jambe which confirms that this is the hottest flame we have seen in the series so far. Even hotter than King and Akainu (although the series logic has magma always hotter than flames).
Ifrit Jambe is the result from the awakening of Sanji’s genetic enhancements combined with his trained Busoshoku Haki increasing his leg’s strength and endurance. With this new technique, Sanji’s legs can withstand much hotter temperature and are thus capable of generating much stronger blue flames, a feat he would have been unable to achieve without his newfound powers.
There is also another detail worth noting. The flames now climb Sanji’s knee and go all the way to his thigh, something they never did before other than when he’s in motion.
Sanji, Luffy and Zoro appear in the center of the Cover, this detail is an implicit move to confirm that the Monster Trio of the Straw Hats remains unchanged.