Crimson Lotus: Fire Dragon's Fist

Flame Lotus: Fire Dragon Fist (紅蓮火竜拳 Guren Karyū Ken): is a Fire Dragon Slayer Magic Spell.

Description
Lighting his hands on fire, Natsu will rapidly punch his opponent. Each punch causes a fiery explosion. This attack was used to defeat Gajeel, the Dragon Slayer that uses Iron, and as an added result, had enough destructive power to destroy the entire guild building of Phantom Lord. In the anime it´s used to defeat Erigor in the Oracion seis arc.