Fire Release: Forge Heat

Fire Release: Forge Heat (火遁・フォージ暑さ, Katon: Fōji Atsusa) is a ninjutsu technique unique to the Mizushima Clan. It is mainly used in their forgeries, but can be used in battle.

Usage
The user creates a large suspended fireball, which reacts to chakra, or objects being wielded by someone or thing that has chakra. When used for attacking, the user can attack up to mid range with chains of fire -- wrapping around the target and pulling them into the suspended orb.

In general, the clan uses it to super heat metal to make it more malleable and suitable for smithing.