Kept secret by the Jakobs family, the Graveward's vault lay undisturbed for centuries beneath Jakobs Estate. Given holy charge to find the Eden-6 vault, the Children of the Vault assault the planet, while the Calypso Twins arrange a lethally hostile takeover of Jakobs corporation, acquiring by proxy not only the family's company, but its estate and, they hope, its secrets.
With vault and key located, the Calypsos—knowing vaults are prisons, but nothing of this prisoner—lure the Vault Hunters into no-escape combat with the captive creature, while Tyreen Calypso waits to feast on its power at death's edge. Defeat follows defeat, however, as the dying Graveward's power is stolen from Tyreen by Patricia Tannis.
Where it glows yellow, the Graveward is vulnerable. Well-defined circular areas of its chest and head provide small, dependable targets, having damage multipliers of 1.4 and 1.2, respectively. Targets of opportunity include the large, glowing orbs in its left hand and right arm (2.5 multiplier). Both are revealed after the impact from its attack to the respective side destroys part of its armor.
The Graveward begins fighting by tilting the entire arena and sending a spread of corrosive spheres rolling downslope. Meanwhile, players slide toward fatal falls from the arena's edge. Halt sliding by either jumping continuously, or sheltering in arena floor pits. (Avoid Snowdrift Artifacts, because they increase sliding.) This attack recurs occasionally between the Graveward's regular attacks, which target halves of the arena: left or right, front or back. Where it attacks next, the floor glows, aiding dodges. Initially, there are four such attacks:
- A straight punch with the right arm, dealing radiation damage to the left half of the arena.
- A right hook along the back, dealing radiation damage.
- Can rarely be replaced by a left swing that covers the same area.
- A left-handed hammer strike, dealing radiation damage to the right half of the arena.
- A corrosive breath attack to the front half while supporting itself on the edge.
After transitioning to phase two of the fight, the Graveward gains two additional attacks. Both are incendiary beam attacks. One shoots several beams from the glowing spots on top of its head, covering a line in the center of the arena, front to back. The other one is a beam from the object in its chest, sweeping across the entire arena. This beam can be avoided by staying at the very back of the arena and jumping over it.
When the Graveward's corrosive breath strikes the arena's front half, Grogs appear, including some corrosive badasses. Similarly, the straight right punch (hitting the arena's left side) spawns Jabbers. Individually, these creatures are not especially dangerous, but their accumulation can be, so precautionary culling reduces risk.
New combat phases begin when Graveward health drops to ⅔ and ⅓. Rearing, falling, and several seconds of stillness signal phase start. While motionless, head crit spots are easy targets—even for shotguns—allowing major damage. When it resumes fighting, attacks and their order are altered somewhat. Normal attack patterns return after an arena tilt, eye beam attack, and chest beam sweep. During such a transition, a health drop across another ⅓ boundary begins the next phase instantly, skipping the rear-fall-rest cycle.