Sonya Mainyu/Labyrinth of Chaos

Sonya Mainyu Battle Theme Sonya Mainyu is the Youma/Doll counterpart of Sonya’s alternate forms. She is the penultimate boss of the Ilias storyline in the middle chapter. Similar to Sonya Mazda, she was formed when Sonya Apoptosis absorbs power form Morrigan. She later evolved into Sonya Chaos after absorbing additional power from Gnosis.

Biography
She is the semifinal boss of the Alice storyline in the mid chapter, formed when Sonya Apoptosis absorbs power from Morrigan. She later evolved into Sonya Chaos after absorbing additional power from Gnosis.

Monsterpedia Entry
"Sonya after awakening as an XX-type Apoptosis, her absorption of dark energy has changed her into this form. Although she boasts tremendous power, there are many uncertainties surrounding her existence, most of which are shrouded in mystery."

Attacks

 * Attack – One Foe
 * Death Blade – One Foe, Physical Attribute, Magic Down 50%, Willpower Down 50%, 3 Hits
 * Hades Blast – All Foes, Physical Attribute, Magic Down 50%, Willpower Down 50%, Death 25%
 * White-Hot Inferno Breath – All Foes, Auto Hit, Fire Attribute, Burn 10%
 * Prominence – All Foes, Magical, Fire Attribute, Burn 10%
 * Ice Age – All Foes, Magical, Ice Attribute, Freeze 10%
 * Plasma Storm – All Foes, Magical, Lightning Attribute, Shock 10%
 * Shadow Flare – One Foe, Auto-Hit, Dark Attribute, Death 10%
 * Energy Draining Latemia – One Foe, Pleasure Attribute, Drain HP
 * Magic Barrier – All Allies, Half Magical Damage for 4 turns
 * Zero Shift – All Foes, Auto-Hit, Dispel

Strategy
A lot of variety in her skills make her a troublesome opponent. Fortunately, she has only limited auto-hit attacks, and an obvious, easy to exploit weakness to holy. Sky dance will reduce damages a great deal, and her magic debuffs aren't an actual issue as most holy spells use willpower. Even with her shield up, you'll deal decent damages to her.

Evaluation
"Hello, this is the Ilias from F3521. Which world's Luka are you? Sonya Mainyu seems to have the power of Darkness. She uses various elemental attacks and she is hard to deal with. She is strong against Wind, Water, Earth, and Pleasure and has normal resistance to Physical, Fire, Ice and Thunder. Focus on those elements. Status ailments rarely affect her. I guess there's no choice but to fight without them... End of transmission, Luka from another world. This is the last message from F35211. Farewell, and keep on fighting Luka, wherever you are. From F35211, this is my last goodbye."

Super Boss Attacks

 * Reaper's Requiem – All Foes, Physical, Physical Attribute, Death 75%
 * 13 the Punisher – One Foe, Physical, Physical Attribute, Death 50%
 * Purgatory Flame – All Foes, Auto-Hit, Fire Attribute, Burn 10%
 * Demon Flame Dance – All Foes, Auto-Hit, Fire/Dark Attribute, Burn 10%
 * Demon Ice Burial – All Foes, Auto-Hit, Ice/Dark Attribute, Freeze 10%
 * Demon Thunder Dust – All Foes, Auto-Hit, Lightning/Dark Attribute, Shock 10%
 * Shadow Flare – One Foe, Auto-Hit, Dark Attribute, Death 10%
 * Fire of Judgement – One Foe, Auto-Hit, Fire/Dark Attribute, Burn/Death 75%
 * Anri-Manyu – All Foes, Auto-Hit, Dark Attribute, Death 75%
 * Semen Extractor of Ra – One Foe, Physical, Pleasure Attribute, Bind 75%, HP Drain
 * Magic Reflect – Self Buff, 2 turns, +100% Magic Reflection, 3 Turns Cooldown, 20 MP
 * Zero Shift – All Foes, Auto-Hit, Dispel, 5 Turns Cooldown, 20 MP

Super Boss Strategy
She is one of the harder super bosses in the Labyrinth of Chaos. Fight her like you would any other super boss. Stack Vicarious Clara, stack your stats, debuff hers. Then attack her. However, you want to keep these things in mind: Check here and here for detailed information on all the superbosses and everything you can make use of to defeat them.
 * She is completely immune to Physical, Bio and Sonic attacks. Any certain Hit attack that deals those types of damages will heal her, making Makina skills inefficient. However, she is weak to most elements, making magical skills the best source of damages.
 * She possess a self buff reflecting magical attacks. Dispel (Priest) counter it.
 * She can inflict both party wide instant death and Ascension. Bringing a Kitsune Geisha for her Anti-Death Song is vital to countering this.
 * She also has certain hit attacks which inflict Burn, Shock and Freeze. Vicarious Clara can deal with these attacks, as it will prevent them from landing in the first place.
 * She has an attack which inflicts single target Bind. Again, Vicarious Clara should be able to protect you from this.
 * She can be slowed/stopped and debuffed, making Sea Palace Maikos and Taoist effective.

A battle against her with only part 1 equipment, no Crisis Hairpin and no stats upgraded can be seen in this video. 

Trivia

 * Angra Mainyu is the Avestan-language name of Zoroastrianism’s hypostasis of the "destructive spirit". The Middle Persian equivalent is Ahriman.
 * It should be noted that Sonya Mainyu borrows the wrong word fragment from the term Angra Mainyu (since Mainyu literally means: spirit, essense, gem) therefore Sonya Mainyu literally means: spirit of Sonya.