Bones of Rathma

Bones of Rathma is a Class Set for s in Diablo III, obtainable at level 70. It can only drop on Torment difficulty.

All set pieces are restricted to Necromancers. Even transmogrification of these items is only available to Necromancers.

The set is named after Rathma, is bones-themed visually and focuses on minions.

Pieces
The set consists of six pieces, all six of which are required to complete it, and all six are Necromancer-restricted.
 * Rathma's Macabre Vambraces (Gloves)
 * Rathma's Ossified Sabatons (Boots)
 * Rathma's Ribcage Plate (Chest Armor)
 * Rathma's Skeletal Legplates (Pants)
 * Rathma's Skull Helm (Helm)
 * Rathma's Spikes (Pauldrons)

Set Bonus:
 * Permanent Minions reduce the cooldown of Army of the Dead by 0.5 seconds each time they deal damage. Skeletal Warriors spawn faster, and Revived minions no longer expire (2 pieces)
 * Minions are immune to all damage. Gain 1% damage reduction for 15 seconds each time one of the minions deals damage, stacking up to 75 times (4 pieces)
 * Each active permanent minion increases the damage of the Army of the Dead and by 500%, up to 9000% (6 pieces)

The first bonus is independent to Proc Coefficient of the attacks. As of patch 2.7.0, it only applies to permanent minions (not to Skeletal Magi), but in return, also makes the Revived minions permanent.

Note that infinite Revived minions are capped to 10 at a time, making this bonus not as game-breaking as one would suspect. Trying to raise more will destroy the oldest ones. However, Mask of Scarlet Death allows raising 10 empowered minions, each composed of up to 10 corpses, even if each only counts as one minion for the purpose of the set bonuses.

The second bonus offers a multiplicative reduction in all damage received, and each hit has a 100% to add a stack and refresh the duration of all stacks, resulting in near permanent 75% protection.

The final bonus is multiplicative to other similar effects. The buff affects the Revived due to first bonus, as well as Skeletons and Golem. Simulacrum only counts if coupled with Haunted Visions. It takes 18 minions (which is, full Skeletons + Golem + 10 Revived) to get the full effect.

This set works best with Jesseth Arms, which complement the Skeletons damage, as well as damage of other minions. Also couples well with Bonds of C'Lena and Defiler Cuisses.

Development
Originally and until July 10, 2017 hotfix buff, Bones of Rathma 6-piece bonus worked slightly differently:
 * Each active increases the damage of all minions and Army of the Dead by 250% (6 pieces)

This way players would need to summon ten (instead of four) Skeletal Mages to receive the full six-piece set bonus. This made maintaining the bonus time consuming and did not allow damage to ramp up quickly at the start of combat.

Until patch 2.7.0, it relied on skill and minion damage, resulting in a hectic, but not player-dependent gameplay; this was later changed to empower the player's own skills instead.