The Greenhilt Sword is a greatsword (with a green hilt, as the name suggests) and the heirloom of Horace Greenhilt's family, going back at least to Horace's father. In D&D game terms, it is a +5 Starmetal Greatsword of Legacy. Horace used the sword in his adventuring days, to defeat (amongst other foes) the green and red dragons of Reddragonsville. The sword was kept above the Greenhilt fireplace after his death, and returned to use when Roy Greenhilt decided to abandon the Magicians' University for the Fighter College. Roy trained with the sword and used it as his primary weapon.
Before fighting Xykon, Durkon Thundershield blessed the sword with the Disruption spell so that he would destroy Xykon with a single hit, however the lich discovered their plan and used a Shatter spell to destroy it. Roy then decapitated the lich in his rage and threw his body into Dorukan's Gate. Roy then decided to collect the shards of the sword, in order to reforge it. Roy used the broken hilt at one point in his journey to free the Order from a bandit camp and kill the bandit executioner; however, he largely favored an improvised greatclub as a replacement weapon.
Inquiring in town, Roy was told by a dwarf blacksmith that the weapon was forged of pure starmetal, and could not be repaired without it. However, the dwarf was in reality Sabine, who sent the Order into Wooden Forest to recover a piece that had allegedly fallen years ago. The Order slew the dragon guarding the starmetal and retrieved it; however, Roy disappointedly learned the piece was barely the size of his hand.
Upon venturing to Azure City and allying with Lord Shojo, Roy agreed to help on the condition that his weapon be repaired. He learned from the Azure City blacksmith that the sword was not forged of starmetal, yet the piece of starmetal recovered from the dragon's lair could be used to create a starmetal alloy. The improvement increased its accuracy and damage were increased by 25%—essentially turning the weapon into a +5 greatsword—and imbued it with the occasional ability to glow with a green energy that is particularly harmful to the undead.
The triggering condition of the green halo effect seems to be Roy being enraged/angry. One known instance of it manifesting consistently and repeatedly (five times in a row) was when Roy fought Xykon over Azure City. It also triggered once when Roy attacked several Draketooth zombies many months later. When Roy first fought the High Priest of Hel the green flames did not manifest, but later when he became enraged the sword displayed a new ability; the green halo enveloped not just the sword but Roy as well, and it appeared to both heal and empower Roy in that fight. During most or all of his other previous fights in the Southern and Western continents, it did not manifest at all.
Threat level does not seem to be a significant factor, but Roy's emotional state is likely to be one, for most if not all instances of the effect happened when Roy was enraged or conflicted. This theory is evident and almost proved when Roy was fighting the High Priest of Hel, when Roy first learns that it was not Durkon at all, enraging him and triggering that green energy effect. However, after he had knocked "Durkon" into the wall, he seemed to notice the green energy effect for the first time, and it vanishes, probably linked to his sudden calmness.
The effect is not limited to undead, nor even to animated foes. It manifested once when Roy was fighting Sabine, and once against Miko. It did not manifest when Roy decapitated Xykon's zombie dragon mount.
The sword seems to have a number of unknown or unconfirmed properties. During Roy's fight with "Durkon", the sword seems to have healed Roy when its green effect is triggered and for the first time it envelops his whole body. After the fight, Wrecan revealed to Roy that the sword is a Weapon of Legacy. In D&D Weapons of Legacy are weapons of great power which have additional powers that are unlocked when the wielder reaches a high enough level and performs a specific ritual. The additional effects manifested by the blade at the Godsmoot are likely to be one tier of these legacy powers. Legacy Weapons have three tiers, so there either one or two more tiers of powers to be unlocked (depending on whether the basic green flame effect constitutes the "Least Legacy" tier of powers for the sword). Unlocking legacy powers come with a cost to the character. It is unclear what was the legacy ritual which Roy performed to unlock the powers manifested at the Godsmoot. One possibility is that using the sword to destroy Girard's Gate constituted the necessary ritual. Wrecan gave Roy a book detailing the history of past Weapons of Legacy in order to help him better understand his sword and unlock its potential.
The best educated guess that can be made at the moment is that the green halo effect is triggered at least in part by an emotional state of rage. While it is most effective against undead, it can and does (rarely) manifest when Roy is fighting living opponents such as Miko and even inanimate (if magical) objects such as Girard's Gate. It first manifested during a fight against Sabine, when Roy charged while feeling particularly frustrated.
As an heirloom of the Greenhilt family, the sword is a focal point for Eugene Greenhilt's spirit to manifest and communicate with Roy. If destroyed, Roy cannot see or hear his father's ghost. Eugene has manifested twice since the sword was reforged, though the first time was while the Order was under the effect of the Draketooths' final illusion. Furthermore, he cannot appear if other people are present or conscious.
In the Celestial Realm, Horace maintains a copy of his sword because he still thinks of the weapon as his. Roy does not have a copy, as to him the sword is his grandfather's.
- ↑ Comic #442, "We Can Do This the Easy Way..."
- ↑ Comic #861, "You Should've Seen What They Did to His Pelvis"
- ↑ Comic #1001, "Will Save the Day"
- ↑ 4.0 4.1 Comic #1009, "Giving Up Hope"
- ↑ 5.0 5.1 Comic #1010, "Green Means Go"
- ↑ 6.0 6.1 Comic #349, "Every Couple Has Their Quirks"
- ↑ Comic #441, "Getting Ahead and Staying Ahead"
- ↑ Comic #1025, "Mark of Distinction"
- ↑ Comic #408, "Fallsville, Population: 1"
- ↑ Comic #898, "Let's Get Ready to Rumble"