T0 Bossing Guide

Getting in

• Cube a Prime Evil Soul, a Black Soulstone and a Pure Demonic Essence into a Vision of Terror.
• Prime Evil Soul: drops from Mephisto, Diablo and Baal in Hell (Diablo 1 in 21, Baal 1 in 13; Mephisto's rate is not published).
• Black Soulstone: always drops from the last Uber in Uber Tristram, along with the Hellfire Torch.
• Pure Demonic Essence: drops from map bosses. The wiki lists the rate as unconfirmed (about 2%).
• The Outer Void unique map (added in Season 11) has three map bosses that each drop a random pinnacle boss material.
• Leave the Vision on tier 0 (cube it alone to cycle tiers), then use it at the blood fountain in Harrogath. The portal opens for everyone nearby. Only one boss area or map can be opened per game.
• The item text recommends level 80. Since Season 10 you can enter below 80, but you get no experience from the fight below level 80.

Skills, phases and mechanics

• Diablo Clone is immune to all damage if no player is within about 10 yards of him. Ranged builds still have to stand close.
• He uses upgraded Diablo skills. The game files list lightning, cold, fire ring, fire wall, a charge, teleport and a skeleton summon.
• Meteors fall randomly throughout the fight. More meteors and Bone Spirits appear in later phases.
• Bone Spirits come from the Trapped Souls. When one hits a player it leaves a patch of burning ground.
• The fight has four phases. In each phase a wave of skeletons rises: Bone Warriors, Skeleton Archers and skeleton mages of every element. They have 60% poison resistance and 75% poison length reduction, and they cannot be cursed.
• Between phases Diablo Clone becomes immune and casts six especially deadly fire novas in a row. He tries to teleport to the middle of the arena first so the novas line up.
• Diablo Clone cannot be chilled or hurt by Static Field. He has 95% curse length reduction, 75% poison length reduction and a 15% block chance.
• Base stats: 30% resistance to physical, fire, cold, lightning and poison; magic resistance lowered to 20% in Season 11; 10,530 base life.

What kills players

• The six fire novas between phases. Most deaths happen here, which is why fire resistance and fire absorb matter so much.
• Standing in burning ground from Bone Spirits while you fight skeletons or dodge meteors.
• Meteors landing on you while you are busy with a skeleton wave.
• Wandering more than about 10 yards from him: the fight stalls and meteors keep falling.

Resistances and defenses

• Fire is the main threat: get fire resistance to the cap (above 75% max if you can) and add fire absorb.
• Physical damage reduction helps against the melee skeletons and his charge.
• Keep your other resistances capped; the skeleton mages cast every element.
• Carry plenty of rejuvenation potions. Buffs from outside do not carry in.

Hiim PD2 team recommendation (T0 / T2): Fire 90% | Fire Absorb any T0 / 12% T2 · PDR 25% T0 / 50% T2

Strategy and positioning

• Recast your buffs first, then stay close to Diablo Clone the whole time so he can take damage.
• Keep moving. Don't let meteors or Bone Spirits land on you, and step out of burning ground right away.
• Clear the skeletons as they come. Since Season 12 he no longer starts the nova phase while skeletons are still alive, so a slow skeleton clear just delays the next nova phase.
• When he goes immune and moves to the middle, get ready for six novas: top up life, use a potion if needed and keep your distance steady.
• At T0 a death is not the end: you can go back in through one of the extra portals. The boss heals 20%, but cleared phases stay cleared.

Changes that made it easier

• Season 10: fewer tracked meteors, no untargeted meteors during the nova phase, no Bone Spirits during the nova phase, Bone Spirits no longer speed up, meteor explosion size cut from 5 to 3.
• Season 10: Black Soulstone is no longer random; it always drops from the final Uber in Uber Tristram. The level 80 entry requirement was removed.
• Season 11: magic resistance cut from 30% to 20%. He teleports to the middle before the nova phase so novas don't go off misaligned. Prime Evil Soul drops went up (Diablo 1/37 to 1/21, Baal 1/22 to 1/13). The Outer Void map added another way to get materials.
• Season 12: T0 gets three portals and entry invulnerability (with more boss life to compensate). Invisible fire was fixed, the nova phase no longer starts while skeletons are alive, and the Trapped Souls pull less aggro, so summons attack them less.
• Season 13: tier 2 got easier and its exclusive unique rate was set to match tier 1 (1/200). These notes are for tier 2 only; T0 was not changed.

Rewards and drops

• Annihilus, a unique small charm: +1 to all skills, +10-20 to all attributes, +10-20 all resistances, +5-10% experience gained.
• Tiers 1 and 2 add a 1/200 chance for an exclusive unique: Overlord's Helm, Dark Abyss, Itherael's Path, Hadriel's Hand or Aidan's Scar. T0 does not have this chance.

Getting in

• Cube Trang-Oul's Jawbone, a Splinter of the Void and Hellfire Ashes (or a Hellfire Torch) into a Voidstone.
• Trang-Oul's Jawbone: drops from undead enemies (about 1 in 22,500 in Hell). Undead in the Rathma fight can drop it too.
• Splinter of the Void: drops from the Shadow of Mendeln map event ("Evil beckons you from the Void..."). The wiki lists about 40%, unconfirmed.
• Hellfire Ashes or Hellfire Torch: from Uber Tristram. Ashes are just a stackable ingredient version of the torch.
• Keep the Voidstone on tier 0 and use it at the blood fountain in Harrogath. The item text recommends level 80.

Skills, phases and mechanics

• The fight alternates pre-phases and boss phases: pre-phase 1, Mendeln, pre-phase 2, Rathma, pre-phase 3, then Rathma and Mendeln together.
• Pre-phases are waves of mostly undead monsters in three different areas. They drop mana, full rejuvenation and antidote potions; the first pre-phase drops far fewer potions. Burning Souls and Void Watchers here are the only lightning damage in the fight.
• Mendeln (mostly poison, one cold skill): poison ball that bursts into a small poison nova, sludge nova (instant poison damage), cold wave, and Lower Resist. At T0 his Lower Resist is -25% (-29% at T1, -33% at T2).
• Mendeln's events alternate, starting with golems. Blood golems: he teleports to the middle and summons four blood golems that walk to him and heal him if they reach him. Vines: he teleports to the middle, casts poison vines with a poison cloud around the edge of the arena, then ends with a deadly poison nova with a very long poison duration. He is immune until the golems are gone or the nova is cast. In the final phase he does not summon golems.
• Rathma (magic damage): a bone spear that leaves a burning trail and hits for a percentage of your life (it cannot be blocked by Weapon Block or Holy Sword or avoided by Evade or Dodge), Teeth, a bone nova that leaves a burning ring at max range, a triple teleport and bone spear combo, and Conjured Souls that cast fissure (fire).
• At 70%, 50% and 30% life Rathma summons Void Knights and is immune until all of them are dead: 70% brings 1 cold, 2 fire, 1 poison; 50% brings 1 cold, 1 fire, 2 poison, 1 physical; 30% brings 2 cold, 2 fire, 1 poison, 1 physical. A knight's damage matches the color in its right hand (red fire, blue cold, green poison, purple physical), and knights can curse.
• In the final phase the two bosses share life: damage to one also damages the other. Both are immune while Void Knights are up.
• Rathma resists: 30% physical, 25% magic (lowered in Season 11), 75% fire, 50% cold, 50% lightning, 0% poison. Mendeln: 30% physical, 25% magic, 65% fire, 40% cold, 40% lightning, 0% poison.

What kills players

• Mendeln's poison nova at the end of each vine event, with its very long poison duration.
• Rathma's three-in-a-row teleport bone spears. They hit for a share of your life and can't be blocked or dodged.
• Burning ground from bone spear trails and the bone nova ring.
• Glacial spikes from the Ancient Spires in Mendeln's arena.
• Void Knights stacking elemental damage and curses while the bosses keep casting.
• Mendeln's Lower Resist cutting your resistances further while all of this happens.

Resistances and defenses

• Poison and cold are the big ones: go well above 75% (max resist) and add poison length reduction to shorten the long poison.
• Overcap all resistances to offset Mendeln's -25% Lower Resist at T0.
• Keep fire capped for the fissures, burning trails and fire Void Knights.
• Lightning is the one element that barely matters here.
• Stock antidote and rejuvenation potions early; the first pre-phase drops very few.

Hiim PD2 team recommendation (T0 / T2): All-Res Overcap 25% T0 / 33% T2 · Psn 85% T0 / 90% T2 · PLR 100% T0 / 150% T2 · Cold 85% T0 / 90% T2 · Fire 85% T0 / T2

Strategy and positioning

• Use the pre-phases to refill potions and belt before each boss phase.
• Against Mendeln, kill the blood golems before they reach him, or they heal him. During vines, stay away from the arena edge and get clear before the final poison nova.
• Against Rathma, keep moving so the teleport bone spears and burning trails don't pin you. Kill Void Knights fast; he is immune until they are dead.
• Deal with knight colors that threaten you first (for example the physical knight for low-PDR builds, poison knights for low poison resistance).
• In the final phase, damage either boss. Their life is linked, so spread damage however is easiest.
• At T0 you can re-enter through an extra portal after a death. The boss heals 20%, but cleared phases stay cleared.

Changes that made it easier

• Season 10: Splinter of the Void drop rate from the Shadow of Mendeln event doubled. The level 80 entry requirement was removed.
• Season 11: Rathma and Mendeln magic resistance cut from 35% to 25%, Conjured Soul magic resistance from 50% to 40%, and Mendeln's phase 1 towers made untargetable. A bug that halved phase 1 Mendeln's lightning resistance was fixed.
• Season 12: T0 gets three portals and entry invulnerability (with more boss life to compensate). Later waves had too few monsters and now spawn as intended, and fissure skeletons no longer spawn outside the arena.
• Season 13: tier 2 got easier (less minion life, lower resistances, less Rathma teeth and ground fire damage), and T2 drop rates now match T1. These changes are listed under tier 2.

Rewards and drops

• A Tainted Worldstone Shard, used to corrupt Annihilus. Each of +1 to all skills, +20-25 Vitality and +10-15 Energy, +5-10 all resistances, or +3-5% experience has a 20% chance; there is also a 20% chance the charm turns into a random magic small charm.
• Tiers 1 and 2 add a 1/200 chance for an exclusive unique (The Third Eye, Band of Skulls, Cage of the Unsullied) and small chances for a Horadric Navigator, Horadric Almanac or Skeleton Key. T0 does not have these.

Getting in

• Cube a Demonic Insignia, a Talisman of Transgression and Flesh of Malic into a Shadow of Hatred.
• Demonic Insignia: drops from enemies in the Act 5 red portal zones in Hell (Abaddon, Pit of Acheron, Infernal Pit).
• Talisman of Transgression: drops from enemies in corrupted zones.
• Flesh of Malic: drops from demon enemies.
• The Outer Void unique map's bosses can also drop any of the pinnacle boss materials.
• Tier 0 was added for Lucion in Season 11. Keep the Shadow of Hatred on tier 0 and use it at the blood fountain in Harrogath. The item text recommends level 80.

Skills, phases and mechanics

• Lucion and all his minions are monster level 110. He cannot be frozen.
• Lightning nova in two waves: a slow, short wave followed by a fast, big wave. The second wave does huge lightning damage.
• His other skills, from the Season 13 game files (not documented on the wiki): Punish (a marker on the ground, then a lightning strike on it), Royal Fire (lightning bolts across the arena), Bone Wave (a line of physical bone spikes), and Blink and Dash (a teleport or dash that ends in a stunning nova).
• Since Season 12 all of Lucion's attacks ignore two thirds of your block chance, including weapon block and parry. His minions are still blocked normally.
• All resistances are 30% and he has a 15% block chance. The wiki lists 24,000 base life, more than the other pinnacle bosses.

What kills players

• The fast second wave of the lightning nova. Getting caught in it is the classic Lucion death.
• Punish strikes and royal fire landing while you are dodging the nova.
• Being stunned by an Anguished Mother or a blink nova right as a lightning wave comes.
• Letting portals pile up minions until the room is crowded.

Resistances and defenses

• Lightning is the key resistance: overcap it so you stay at the cap, and use lightning absorb if you can.
• Physical damage reduction for the bone wave, dash and minions.
• Don't rely on block: he ignores two thirds of it.

Hiim PD2 team recommendation (T0 / T2): Light 90% · PDR 50%

Strategy and positioning

• Recast your buffs, then deal with portals and minions before the room fills up.
• Learn the nova timing. A common community tip: when the slow first wave starts, move onto Lucion, then walk straight away from him down an empty lane before the fast wave expands. Moving straight out beats zig-zagging.
• Some players say WASD movement (added in Season 11) makes dodging the waves much easier.
• Watch the ground for Punish markers and step off them.
• At T0 you can re-enter through an extra portal after a death. The boss heals 20%, but cleared phases stay cleared.

Changes that made it easier

• Season 10 patches: Lucion's portal life cut by about 17%, Anguished Mother stun cut from 2 seconds to 1, ground effects now show in the right place.
• Season 11: Lucion tier 0 was added, and a bug that made his phases slower in higher tiers was fixed.
• Season 12: T0 gets three portals and entry invulnerability (with more boss life to compensate). A safe spot in the arena was removed, and his attacks now ignore two thirds of block.
• Season 13: desecration chances raised from 40/50/60% to 50/60/60% (T0/T1/T2). Tier 2 also got easier. Act 5 portal density in Hell went up by about 67%, which should make Demonic Insignia easier to farm (our reading; not stated in the notes).
• The Season 11 and Season 13 notes give different old desecration chances (50/55/60% vs 40/50/60%). The current wiki value for T0 is 50%.

Rewards and drops

• Access to the Temple of the Triune. Place an amulet on the sacrificial altar to desecrate it: it gets a second corruption from the high-rarity amulet pool (+1 all skills, 10% FCR, 10% FRW, 10% curse resistance, 30-40% ED, Cannot Be Frozen, +2% all max resistances, or 7-10 all resistances).
• The T0 desecration chance is 50% (60% at T1 and T2). If it fails, the amulet turns rare and keeps two random corruption mods.
• Golden chests in the temple drop one more item per tier, so T0 chests drop the fewest.
• The Demonic Cube (a rare drop at 1/75) only drops from Lucion at tier 1 and 2, not T0.