The name of the Flame Regalia is believed to be Key 'Mother'. The Infinite Atmosphere ability of the Flame Regalia is Infinity Inferno. The core appears to be the wheels, and is decorated by a nine-tailed fox with flames at the end of each of its tails. Because fire is considered to be the creator of everything these Regalia are able to imitate the power of other Roads when fully awakened.
The Flame Regalia originally belonged to Spitfire, but lost them during the fall of the first Sleeping Forest. They were given to other riders, eventually being regained by Spitfire. Before dying Spitfire passes the Regalia to Kazu, but the Regalia were later stolen by Aeon Clock. During the battle with Nike, Aeon tunes them to Kazu who then uses them to defeat Nike. After Nike was defeated, ending the fight on Genesis's carrier, Kazu gave the Flame Regalia Core to Ikki.
Infinity Inferno: The Infinity Atmosphere of the Flame Road. Its exact
effect is unknown, but it appears to increase the strength and speed of the users "flame".
Apollo Road: ST. Elmo's Crossfire: An Apollo Road trick created by Aeon Clock and Spitfire. The friction of the two ATs causes extreme fires that burn the opponent. Spitfire and Aeon used it against Nike, but Nike had neutralised the damage with his Jade Road, so this tricks exact power is unknown, but is presumably extremely powerful. When used by Kazu alone on Nike, the flames nearly leveled the entire aircraft carrier.
Time: A series of tricks performed by Kazu, Spitfire and Aeon Clock. Used to give the illusion of controlling time by repeatedly striking the opponents joints and the weak nerve ends of a human's body. This makes the opponent feel a burning sensation, thus being classified under the Flame Road. Aeon Clock's moves are focused exclusively on this trick and he has even developed a series of "Time" sub-tricks.
Hole Nine Heaven's Gate [Ættir]: The activated Flame Regalia has the ability to tap into Skylink and copy the tricks of other roads. This shapes the user's flames into ghost-like copies of the original riders. If the wielder of the Flame Regalia isn't strong enough to use those tricks on his own, however, this technique is said to burn up the user's life as well. Tricks can only be copied if the original user grants access to the Flame King.
ST. Elmo's Crossfire is a reference to the natural phenomena that may occur before lightning is made.