Yen-Lo-Wang, named after the Chinese god of death, is a famous individual BattleMech. Its serial number is FS1010-031X. Yen-Lo-Wang has been modified and customized into a variety of different configurations over the years.
Justin Xiang Allard
Yen-Lo-Wang was originally an old regular Centurion that Justin Xiang Allard purchased in 3027 with funds provided by Kym Sorenson during his exile on Solaris VII and his Solaris Championship run. He modified the 'Mech to carry an Autocannon/20, which gave him a surprise advantage in his first match using Yen-Lo-Wang where he defeated Peter Armstrong. At some point he placed titanium "nails" on the 'Mech's hand actuators, a feature put to good use in a fight against Billy Wolfson where the autocannon jammed.
When Justin Xiang Allard was extracted from Sian at the climax of the Fourth Succession War, Yen-Lo-Wang was also taken along.
Justin Xiang Allard gifted the 'Mech to his son, Kai Allard-Liao, when Kai first joined the Armed Forces of the Federated Commonwealth. There, Kai served with distinction and saw action in the 'Mech during the Clan Invasion. Hanse Davion personally had the 'Mech modified with Star League-era technology after Kai refused to accept a Wolf's Dragoons-produced Daishi assault OmniMech, officially presenting the upgraded Yen-Lo-Wang to Kai on 21 September 3050. The weapons had been replaced with a Von Ryan Gauss Rifle in place of the autocannon and Spitfire Medium Pulse Lasers, two on the arm, one on the torso and one on mounted on the back. Additionally, the 'Mech was refitted with a new generation of Triple Strength Myomer that did not burn when exposed to gas, the Miata 200 extralight engine, and three additional, switchable Heat Sinks. The 'Mech was briefly lost behind Clan Jade Falcon lines on Alyina, but Kai later recovered it. Its gauss rifle was recovered by a Jade Falcon garrison he was temporarily allied with against ComStar's Operation Scorpion machinations on the planet, used to launch a girder to batter down a ComStar complex's door in their operation to liberate the planet from ComStar control.
Notably, Kai Allard-Liao would not pilot Yen-Lo-Wang in his arguably most famous combat action: He was separated from his 'Mech, which was being transported on another DropShip, and thus borrowed a Hatchetman for the Battle of Twycross in 3050. There, he ended up self-destructing the Hatchetman and using its Full-Head Ejection System to save himself and Dr. Diedre Lear, who was riding shotgun, while demolition charges which were activated through the explosion of the Hatchetman buried the entire Falcon Guards in a canyon.
Later, he used Yen-Lo-Wang as he followed in his father's footsteps as Solaris VII Champion.
Yen-Lo-Wang saw service again with Kai in the final assault of New Avalon island in 3067, protecting Victor Steiner-Davion from harm. In the first stages of the battle, however, it was piloted not by Kai but by Thomas Sherwood and deployed in a diversionary attack with Archer's Avengers to reinforce the impression it was the real main assault.
Though long retired from the battlefield, Kai would pilot Yen-Lo-Wang a final time during the Capellan Crusades, the unmistakable 'Mech cutting a bloody swath through the CCAF like its namesake as its pilot sought vengeance for his deceased daughter Melissa Allard-Liao. Facing off against the combined might of the elite Red Lancers and Death Commandos sent to kill him personally on Sakhalin, Kai would ultimately fall on 14 January 3113 after a stray missile strike hit Yen-Lo-Wang in the head. As a sign of respect for Kai's legacy, the Death Commandos chose to leave Yen-Lo-Wang right where it fell rather than claim it as salvage, attaching a beacon so that the Republic of the Sphere forces could locate and retrieve it.   
Feeling a kinship with young Danai Liao-Centrella, among Kai's final words was his desire that Yen-Lo-Wang be bequeathed to her. By the time she had come of age, Yen-Lo-Wang had fallen in disrepair and needed extensive restoration. In the early 3120s, when Danai was old enough, she journeyed to gather parts to restore the 'Mech. She then used it on Solaris VII, where she competed in the games and won the Solaris Open with it. She and Yen-Lo-Wang went into service with House Liao's Second McCarron's Armored Cavalry as part of the 3130s incursion into the Republic of the Sphere. 
Armament & Configuration
Succession Wars era
In its original form as purchased by Justin Xiang Allard, Yen-Lo-Wang was apparently an old regular Centurion, implicitly a standard CN9-A model. It was then refitted with a bigger autocannon at the cost of secondary armament, to what seems to be CN9-AH specs.
At some point Yen-Lo-Wang was modified beyond CN9-AH specifications. This variant was referred to as CN9-YLW, though it remains unclear if that denomination refers to the specific 'Mech or to its specific configuration. The CN9-YLW was armed with an Autocannon/20 in place of the standard model's Autocannon/10, two Medium Lasers and a Hatchet. Apparently, the hatchet originally took the form of functionally identical titanium nails which were eventually replaced with a proper hatchet.
It was also noted that, because of its background as a high-profile champion 'Mech from the Solaris Games, Yen-Lo-Wang was equipped with additional diagnostic and telemetry systems, though these did not grant any immediate advantage in combat.
Clan Invasion era
Dark Age era
Refurbished as Kai Allard-Liao prepared for his berserker drive against the Confederation, at the time of his death Yen-Lo-Wang was armed with Clan-tech weaponry - a Gauss Rifle and LRM-20 launcher both supplied with two tons of ammo each, supported by a single head-mounted ER Medium Laser and hatchet. Aside from the weaponry, CN9-YLW3 Yen-Lo-Wang's chassis remained Inner Sphere grade, the double heat sinks, triple-strength myomer and XL engine remained unchanged, with the armor upgraded to Light Ferro-Fibrous.  
After passing to Danai Liao-Centrella, the ancient 'Mech featured a Series 4D-2 Heavy Large Laser, a Type XX "Long Bow" LRM-20 with Artemis IV, a Hatchet, a Shield, and Triple Strength Myomer; it was noted to feature experimental Clan technology though it remains unclear to which components exactly this refers. By this time, its chassis had been replaced with a Corean Model K77 Endo Steel chassis and it was powered by a Vlar 300 XL fusion engine.
Image thought to depict Yen-Lo-Wang, facing an opponent in the Solaris VII arenas.
BattleTech Trading Card Game image of Justin's CN9-YLW variant
Yen-Lo-Wang as envisioned in MechWarrior Online
- In the novels Fortress Republic and Principles of Desolation, the refitted Yen-Lo-Wang piloted by Danai Liao-Centrella is described, showcasing its configuration. A dossier card showing some of its featured weapons and equipment was also provided. However, as of this writing there is no canonical record sheet provided for this particular version of Yen-Lo-Wang.
- Danai Liao-Centrella's dossier card
- Warrior: En Garde, pp. 138-139
- There are no game rules for those titanium nails. Judging from the 3027-era record sheet published for the CN9-YLW, a 'Mech hatchet—the only 'Mech melee weapon that existed in the rules when the novel introducing Yen-Lo-Wang was written—was used to represent the nails in game terms. (Notably, Yen-Lo-Wang was never ruled to have featured a 'Mech Claw.) This stand-in in turn apparently resulted in art depicting the 'Mech with a proper hatchet.
- Blood Legacy
- The Longest Road, pp. 26-27
- Historical: Wars of the Republic Era, p. 7 "Righteous Vengeance - 1919 Hours"
- Operation Turning Point: Capellan Crusaders, p. 9 "The Crusades"
- Operation Turning Point: Capellan Crusaders, p. 25 "Touchpoint: Sakhalin"
- Era Report: 3145, p. 87
- Record Sheets: 3025 & 3026; Record Sheets: 3039, p. 121
- Record Sheets: 3050 Upgrade Unabridged (Inner Sphere), p. 124
- Operation Turning Point: Capellan Crusaders, p. 34 "Centurion CN9-YLW3 "Yen Lo Wang" "
- Principles of Desolation, pp. 78-90, 98-99
- Blood Legacy
- Danai Liao-Centrella's Dossier
- Era Report: 3145
- Fortress Republic
- Historical: Wars of the Republic Era
- Lethal Heritage
- Lost Destiny
- MechWarrior Online (MWO Hero 'Mech)
- Operational Turning Points: Capellan Crusades
- Principles of Desolation
- Record Sheets: 3025 & 3026
- Record Sheets: 3039
- Record Sheets: 3050 Upgrades Unabridged (Inner Sphere)
- The Longest Road
- Warrior: Coupé
- Warrior: En Garde
- Warrior: Riposte