|Manufacturer||Arcadia BattleMech Plant CM-T4|
|'Mech type||Clan BattleMech|
|Chassis||Star League XT|
|Armor||Mk. VI ferro-fibrous w/ CASE|
|Communications System||Hector CC-22E|
|Targeting Tracking System||Brim CT-37 Mk. XII|
|Heat Sinks||17 Double heat sinks|
|Speed||65 km/h (86 km/h with MASC)|
Following the development of Heavy Laser technology, Clan Star Adder scientists sought a testbed on which to mount the lasers. For this purpose, they resurrected the Lupus, a first-generation OmniMech that had been relegated to second-line units or put into storage in Brian Caches. Seeking to rebuild the understrength post–Burrock Absorption Star Adder touman, upon learning the heavy lasers worked so well on the Lupus, Khan Cassius N'Buta ordered more Lupuses be refitted en masse. From 3058 on, Arcadia BattleMech Plant CM-T4 had refitted over a hundred Hellfires for Clan Star Adder as well future-Snake Alliance allies Clan Cloud Cobra. Deployed in significant numbers among the Star Adders' second-line galaxies, a moderate number have fallen into the hands of other Clans who've faced the Adders. 
Weapons and Equipment
For weaponry, the Hellfire utilizes an array of heavy lasers. At medium range, a Series 4D-2 Heavy Large Laser and twin Series 7JA ER Medium Lasers are the go-to weapons. The armament excels at short range, when two Series 6A Medium Heavy Lasers and two Series 14 k. II Heavy Small Lasers can be brought into play. The most significant different between the testbed and final refit models is the addition of three "Longbow" III LRM-10 launchers to provide some ranged firepower. Though the heavy lasers are inherently inaccurate, the incredible damage output makes this 'Mech feared. Seventeen double heat sinks are woefully inadequate to keep heat levels under control, so MechWarriors must take extreme caution. 
To carry such a heavy loadout, the Hellfire uses a smaller engine than the Lupus, so it only has a top speed of 65 km/h. Though originally intended to retain the Lupus's 300-rated engine, Kappa Provisional Galaxy Commander Jenica Turgidson who was overseeing development insisted on a smaller engine, arguing that as the Hellfire was intended for defensive roles it needed firepower ahead of speed. She did agree to the inclusion of MASC for quick bursts of extra speed to close with or retreat from the enemy. The Hellfire mounts nine tons of ferro-fibrous armor. 
Despite its initial success, the combat service of the Hellfire has not been flaw free. Aside from the sensor interference caused by firing its signature Heavy Lasers, a number of battlefield reports indicate the heavy laser tubes can violently rupture in the heat of battle. The 'Mech also experiences a fifteen percent higher rate of MASC failure than usual, though technicians have yet to determine whether this is due to the age of the Lupus chassis or if this is something caused by the Heavy Lasers.  
- Hellfire 2
- Approximately twice as expensive as the original, the Hellfire 2 uses an 300-rated XL engine to increase the 'Mech's speed to 86 km/h. In place of the LRMs are a pair of ATM 6s. The heavy smalls are replaced with a single ER Small Laser and an additional double heat sink. BV (1.0) = 1,793, BV (2.0) = 2,370
- Hellfire 3
- A smaller XL engine reduces this variant's top speed to 64 km/h, but the MASC system allows the 'Mech to top out at 86 km/h for short bursts of speed. The weaponry has been replaced: The side torsos each carry a single SRM-6, while each arm carries an ER Flamer, Flamer, and two Plasma Cannons. Fifteen double heat sinks dissipate the massive heat load generated by the weaponry. BV(2.0)=2,138
These variants were introduced in various apocryphal sources, and thus far have not appeared in any canonical media.
From MechWarrior Online:
- The Hellfire A is built on an Endo Steel and mounts an 240-rated XL engine, clad in standard armor but saving weight for a Gauss rifle and Streak SRM-4 in the right torso, paired Streak SRM-6s in the left torso, supported by a single Heavy Medium Laser in each arm. Fitted with MASC like the standard Hellfire to make up for lackluster ground speed, the A mounts thirteen double heat sinks and carries three tons of Gauss reloads and four tons of Streak missiles.
- The B mounts the 300 XL engine of the Hellfire 2, but swaps the ferro-fibrous armor for an Endo Steel chassis, using the weight saved to mount a Heavy Large Laser and LRM-15 in the left torso, twin Streak SRM-6s in the right torso, supported by a Heavy Medium and ER Medium Laser in each arm. Carrying MASC to boost its mobility, the Hellfire B is fitted with eighteen double heat sinks and carries two tons of Streak and one ton of LRM missiles.
- The Hellfire C is built on the basic frame of the B variant, though swaps back to ferro-fibrous armor, is armed with an ER Large and ER Medium Laser in arm supported by an ATM 6 in each side torso. Again retaining the MASC of the other Hellfire variants, the C model features eighteen double heat sinks and a combined four ton ATM ammo bay to draw upon.
- HLF-VO VOID
- The Hellfire Hero 'Mech reportedly piloted by Delta Galaxy's Galaxy Commander Vanel Talasko, the Void features the base chassis and MASC of the C but is armed with an Ultra Autocannon/10 and SRM-6 in the right torso and an Ultra Autocannon/5 in the left arm, supported by twin Heavy Mediums in the left torso and a twin of Heavy Small Lasers in the right arm. Void is fitted with fourteen double heat sinks and carries four tons of UAC reloads and a single ton of SRM missiles. 
- Lupus - Many Hellfire chassis were taken from Clan Coyote's Brian Caches and converted into BattleMechs while renaming the Mech.
- In German products, the unit's proper Clan name was translated to Höllenfeuer.
- Technical Readout: 3067, p. 120-121
- Record Sheets: 3067 Unabridged, p. 210
- Field Manual: Crusader Clans, p. 188 "Rules - Hellfire"
- Era Digest: Golden Century, p. 24
- Hellfire Lore And Blueprint
- Combat Operations, p. 110
- Record Sheets: 3067 Unabridged, p. 211
- Record Sheets: 3067 Unabridged, p. 212
- MechWarrior Online Hellfire Sale Page
- BattleMech Manual, p. 92 BattleMech Quirk Table -Hellfire Entry.