“MTWOTFFTO. (One of the five great elements from which the world is constructed.) IIGOIIOF. (The great flame of the beginning.)”

[...]

“IIBOLAIIAOE. (It is a light of blessing that raises life and a light of judgment that punishes evil.) IIMHAIIBOD. (It is overflowing with calm blessings and with freezing misfortune that destroys cold darkness.) IINFIIMS. (Its name is fire and its role is the sword.) ICRMMBGP! (Be manifested and become the power that eats into my body!)”

[...]

It was not merely a mass of flames.

The crimson burning flames had something black and dripping like fuel oil at its core. It was in the form of a human. The thing was reminiscent of the seabirds dripping with black fuel oil after a tanker accident, and it was eternally burning.

Toaru Majutsu no Index vol.1 ch.1 pt.6