Seria says: "Nothing should be as mysterious as I am!"

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Pureblood Despero

Age	Unknown
Sex	Male
Race	Imposter
Affiliation	Black Order
Occupation	Pureblood
Alias
Location	Black Purgatory - Destroyed Los Chest
Foreign Name(s)	N/A
Likeability	N/A

Pureblood the Despero is a Black Order member and Pure Blood recipient to Despairing Tiamat who was captured by the Lemidia Capella only to be set free by Timor, kicking off the events surrounding Black Purgatory.

Despero's Human appearance

Lore

Black Purgatory Exerpt:
Hot, burning pain sizzled against his skin.

They had thrown at him their so-called holy water and flames of purification a hundred times over.

His body was hanging limp, refusing to move as he wanted.

All he could do was laugh.

He took pity on these fanatics. They were obsessed with their god's false messages and happily threw their flames at anyone they saw.

You think you can make me despair with your ticklish flames.

You expect me to beg you for my life.

The despair he gave me, the chaos he beholds, is deeper and more fulfilling than anything you can imagine.

Suddenly the air in front of him shimmered, and she walked out of the warped space.

The wardens at his cell door fell like dead leaves.

Ah... finally...

The door was destroyed, and two booted feet stood in front of him.

The chain that had bound him fell to the ground with a loud clang.

He limply fell to the ground.

"It's time you show them despair again, Despero."

Ah, my Chaos—my Despair! I've been waiting for this day!

Foolish fanatics,

Now, I'll show you what true despair is.
^[1]

As an Enemy

Despero makes his first boss debut in the Black Purgatory dungeons inside Cradle of Despair. He later returns in Ozma of Chaos Raid as Chaos Follower Despero.

Move Set

Energy Explosion: Despero powers up and unleashes a AoE explosion around him.

Black Spear: Despero jumps into the air as he scatters volleys of black spears all over the map, then lands down to have those spears with a circular trajectory around them explode after a while, inflicting wide-area damage.

Black Spear Discharge: A variation of Black Spear that instead has Despero releases a spear from his shoulder and throws it upwards to scatter around the map, exploding afterwards.

Black Spear Throw: Despero throws a spear forward like a projectile that leaves more of them sticking onto the ground.

Swoop: Despero goes airborne and attempts to strike the ground at a targeted player up landing, being identical to Golden Wing Tritura's Strike Down, albeit downscaled.

Triangle Dash: He'll dash three times in a triangle-shaped direction, then attacks around the third dash.

Berserk:

I'll bury you. Heh heh: The map darkens to black as Despero disapears, throws volleys of Black Spears raining down across the map. Meanwhile, one party receives a blue barrier that acts like a Nen Guard and is able to see a pulsing green Y-axis diagonal line, another member gets a blue coil around them and can see a blue pulsing X-axis veritcal line. To clear this pattern correctly, both players that have a blue barrier and coil respectively are required to seek out a intersection between the lines and must guide party members who cannot see either lines into a considered safe-zone area while avoiding being attacked.

Once the timer gauge fills up, Despero reappears and performs a instant kill party-wipe explosion and if everyone is in the safe-zone intersection, it forms a green barrier that gives them protection from the attack before fading away. This pattern's setup is very similar to Dog Head's Omerta!.

Electric Marble: Despero gets into the middle section and launches out Black Spears that leaves three different colored circles. Red Circles leave a randomly placed explosion, while White & Green ones follow party members and in order to clear this pattern sucessfully, everyone must overlap three either White or Green circles of the same color to generate a electric orb and hit one of each directly at Despero at least three times to generate his groggy. Failure to meet the requirements results in a AoE party-wipe explosion.

Laughter: Despero screams three times as he forms a red circle that's able to pull anyone towards him and his Black Spears are able to inflict a stun status. For this pattern to succeed, there's light green circles near Despero's red circle range that must require at least three party members to stand on three of those circles two times. If the pattern is done correctly, Despero's circle turns yellow and he'll generate his groggy afterwards.

Strategy

Despero of the Black Order Follower Trio isn't as difficult or aggressive with his moves compared to either Jett or Midnight during their boss fights, though some of the berserk patterns can be fatal if players do not coordinate.
During I'll bury you. Heh heh, make sure you and the other player that either has their respective blue/green pulsing lines give a signal to party members who cannot see those lines where the safe-zone intersection as a heads up.
If you place an opposite White/Green circle color on top of another during Electric Marble, they'll disappear so do be mindful of both your location and circle color due to how chaotic this pattern can be.
Depending on the strength of your party members, Black Purgatory's route chosen and alongside obtaining specific buffs through rescused APCs or defeated Followers, have the Crusader/Enchantress deploy their Apocalypse/ Final Judgment, Crux of Victoria/ Laus di Angelus, Marionette/ Curtain Call and use your strongest skills upon entry to burst him down if you don't wish to deal with his patterns.