Sword Art Online: Alicization - War of Underworld Part 2

Sword Art Online: Alicization - War of Underworld Part 2

Characters

Kazuto Kirigaya

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Alice Zuberg

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Asuna Yuuki

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Ryoutarou Tsuboi

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Shino Asada

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Renly

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Pina

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Amayori

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Hans

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Andrew Gilbert Mills

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Fanatio

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Natsuki Aki

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Scheta

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Talken

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Takiguri

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Hoshigami

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Azurica

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Takeru Higa

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Eugeo

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Tecchi

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Yuesheng Zhao

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Danpa

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Deusolbert

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Vassago Casals

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Quinella

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Sword Art Online: Alicization – War of Underworld (Season 4) – A Deep Dive into Virtual Epics and Human Souls

Sword Art Online: Alicization – War of Underworld, the second half of the third season (often referred to as Season 4), represents a bold evolution of the Sword Art Online franchise. Spanning episodes from October 2019 to September 2020, this arc adapts volumes 15 to 18 of Reki Kawahara’s light novel series, diving deeper into the Alicization storyline. It’s a sprawling, ambitious narrative that pushes the boundaries of virtual reality storytelling while grappling with complex themes of artificial intelligence, human consciousness, and the cost of survival. This review explores what makes War of Underworld a standout chapter in the SAO saga, analyzing its narrative depth, character arcs, technical achievements, and philosophical undertones without resorting to hyperbole or promotional fluff.

Narrative and Themes: A War Beyond the Virtual

War of Underworld picks up where Alicization left off, with Kirito (Kazuto Kirigaya) comatose after a real-world attack, trapped in the virtual Underworld created by the Soul Translator (STL). The story centers on a cataclysmic war between the human inhabitants of the Underworld and the Dark Territory, orchestrated by external forces with sinister motives. Unlike earlier SAO arcs, where the stakes were tied to escaping a game, War of Underworld explores a simulated world where artificial intelligences, or Fluctlights, possess souls indistinguishable from humans. This raises profound questions: What defines humanity? Can artificial beings have rights? What are the ethics of creating and controlling sentient AI?

The narrative is split into two cours, covering the escalating war and its aftermath. The first half focuses on Alice Margatroid, a knight of the Underworld, as she leads the human forces against the Dark Territory’s invasion, while Asuna and other real-world players dive into the Underworld to assist. The second half delves into Kirito’s recovery and the final confrontation with the masterminds behind the conflict, including the enigmatic Gabriel Miller and the remnants of Rath’s experiments. The arc’s scope is massive, blending large-scale battles with intimate character moments, though it occasionally stumbles under its own weight, juggling multiple perspectives and plotlines.

One of the arc’s strengths is its exploration of AI ethics. The Underworld’s inhabitants, like Alice, are not mere code but sentient beings with memories, emotions, and agency. The show questions whether their lives are expendable, especially as real-world operators treat them as tools. This theme resonates with contemporary debates about AI development, making War of Underworld feel prescient. However, the narrative doesn’t always delve as deeply as it could, sometimes prioritizing action over philosophical resolution. The concept of Fluctlights—digital souls—offers a fresh twist on the SAO formula, moving beyond the “trapped in a game” premise to a more existential crisis.

Characters: Growth, Sacrifice, and New Faces

War of Underworld shines in its character development, particularly for Alice, who emerges as the arc’s emotional core. Her journey from a loyal knight bound by artificial rules to a figure questioning her existence is compelling. She grapples with her identity as an AI, her loyalty to the Underworld, and her connection to Kirito, whose vegetative state looms over the narrative. Alice’s arc is a highlight, offering a nuanced portrayal of a character caught between worlds.

Kirito, sidelined for much of the first half, undergoes a quieter but no less impactful arc. His internal struggle, depicted through surreal dream sequences, explores guilt, trauma, and redemption. When he finally awakens, his return feels earned, though some fans may find his prolonged absence frustrating. Asuna, meanwhile, takes a more active role, diving into the Underworld to protect Kirito and the Fluctlights. Her steadfast resolve anchors the story, though her character doesn’t evolve as dramatically as Alice’s.

New characters, like the Dark Territory’s Iskahn and Sheyta, add depth to the conflict, showing that even the “enemy” side has complex motivations. The introduction of real-world players, including Sinon and Leafa, brings back familiar faces, but their roles can feel like fan service at times, diluting the focus on the Underworld’s unique inhabitants. The villains, particularly Gabriel, are chillingly effective, embodying cold, utilitarian cruelty. However, some antagonists, like Vassago, lean into clichéd villainy, which undercuts the arc’s more sophisticated moments.

Technical Craft: A Visual and Auditory Spectacle

A-1 Pictures delivers some of the best animation in the SAO franchise with War of Underworld. The battle sequences are a visual feast, with fluid swordplay, vibrant spell effects, and massive set pieces that capture the chaos of war. The Underworld’s distinct aesthetic—blending medieval fantasy with futuristic elements—sets it apart from earlier arcs like Aincrad or Gun Gale Online. Each clash, from Alice’s radiant sword strikes to the grotesque monsters of the Dark Territory, is meticulously crafted, making every fight visually distinct.

Yuki Kajiura’s soundtrack is another triumph, weaving new themes for the Underworld with haunting remixes of classic SAO motifs. The score amplifies the emotional weight of key scenes, from quiet moments of reflection to the crescendo of battle. Voice acting, both in Japanese and English, is stellar, with Yoshitsugu Matsuoka (Kirito) and Ai Kayano (Alice) delivering raw, emotional performances. The English dub, featuring Bryce Papenbrook and Cherami Leigh, maintains the intensity, though some nuances are lost in translation.

However, the pacing can be uneven. The first half builds tension effectively, but the second half occasionally drags with expository dialogue and redundant flashbacks. The sprawling cast also leads to moments where certain characters, like Sinon, feel underutilized despite their prominence.

Strengths and Flaws: A Balancing Act

War of Underworld excels in its ambition, tackling themes of AI sentience, sacrifice, and the blurred line between virtual and real. The focus on Alice as a co-protagonist adds fresh perspective, and the arc’s exploration of Kirito’s trauma humanizes a character often criticized for being overly idealized. The technical execution—animation, music, and voice work—is top-tier, making it a visual and auditory spectacle.

Yet, the arc isn’t flawless. The narrative’s complexity sometimes leads to convoluted subplots, and the reliance on familiar SAO tropes (like Kirito’s inevitable heroism) can feel repetitive. The second half’s pacing issues and occasional fan service detract from the story’s gravitas. Additionally, while the AI ethics theme is compelling, it’s not always explored with the depth it deserves, leaving some questions unanswered.

Cultural Impact and Reception

War of Underworld has sparked varied reactions. Fans praise its emotional depth and stunning visuals, with many on platforms like MyAnimeList calling the Alicization arc the franchise’s peak. Critics, however, note its pacing issues and argue it doesn’t fully escape SAO’s polarizing reputation for inconsistent storytelling. On Rotten Tomatoes, the arc has garnered mixed reviews, with some viewers feeling it strays too far from the original SAO’s charm, while others appreciate its bold new direction.

The arc’s exploration of AI ethics feels timely, resonating with real-world discussions about technology’s role in society. Its global simulcast on Crunchyroll and Funimation, delayed slightly by the COVID-19 pandemic, underscores SAO’s enduring popularity. The franchise’s ability to evolve while retaining its core focus on virtual worlds and human connection keeps it relevant in the isekai genre.

Conclusion: A Flawed but Ambitious Epic

Sword Art Online: Alicization – War of Underworld is a testament to the franchise’s willingness to take risks. It trades the simplicity of the original Aincrad arc for a denser, more philosophical narrative, blending high-stakes action with questions about humanity and technology. While it doesn’t always stick the landing—pacing issues and familiar tropes persist—it’s a gripping evolution of SAO’s core ideas. Alice’s journey, Kirito’s introspection, and the Underworld’s vivid world make this arc a standout, even if it demands patience from its audience.

For fans of SAO, War of Underworld delivers the emotional and visual spectacle they expect, while offering enough new ideas to keep the series fresh. For newcomers, it’s a self-contained entry point (with some context from earlier arcs), though its complexity may overwhelm. Ultimately, it’s a flawed but powerful chapter that pushes Sword Art Online into uncharted territory, proving the franchise still has plenty to say about the intersection of humanity and virtual reality.