I have always believed that the cosmos composes its grandest symphonies not in the birth of stars, but in the silent, inevitable descent of its most luminous souls. The echoes from Penacony have finally solidified into a chilling crescendo: Sunday, the long-anticipated figure first glimpsed in a distant livestream, is no longer merely a character on the horizon. As 2026 unfolds, he prepares to make his debut not as a companion, but as a maestro of ruin within the Apocalyptic Shadow, the very crucible where the Trailblazers' mettle is tested. The whispers have become a storm, confirming that version 2.6, arriving this October, will see him ascend as the boss known as The Great Septimus, a transformation that feels less like an enemy introduction and more like the universe unveiling a tragic, final movement in a celestial opera.

This is not an unfamiliar path within the Astral Express's journey. The line between ally and adversary has always been as thin and shimmering as a strand of Stellaron energy. I recall facing Kafka in the Memory of Chaos, her strings of domination a harsh lesson in duality, and Argenti's chivalrous challenge in the same arena. These encounters taught me that strength often wears many masks. Sunday now joins this solemn roster, but his arrival promises a complexity that eclipses mere combat. According to the revelations, his battle will be a two-act play of devastating beauty. He will wield abilities named Volteggiando and Tempestoso—terms that evoke not mere damage values, but the sweeping, emotional arcs of a symphonic score. His power will be a caged sonata, each note a calculated strike against the harmony we seek to preserve.

The true heart of this confrontation, however, lies in his metamorphosis. In his second phase, Sunday will shed the form of The Great Septimus and become the Embryo of Philosophy. This is a profound shift: he will gain all weakness types, a state that is paradoxically both a vulnerability and a declaration of omnipotence, like a black hole that consumes every spectrum of light. From this embryonic state, he will summon Echoes of Faded Dreams, phantasmal companions with whom he shares a collective vitality. His Tempestoso will not only assail us but rejuvenate their resilience, forcing a strategy that is less about a single target and more about silencing a haunting choir of lost possibilities. His core passive is rumored to deviate from the standard Steardfast Guard, suggesting a mechanic as unique and unsettling as his theme—a clockwork heart ticking backwards towards an unknown zero.

The Stage of Shadows: Apocalyptic Shadow

This is the arena where Sunday's symphony will be performed. Let me recount what this mode demands of us:

• A Dual Challenge: We face two formidable bosses consecutively. Currently, these are the Starbane Doombringer and Soulhook Sovereign (Kafka).

• A Test of Speed and Strategy: Each boss possesses two phases and four unique traits, elevating them far above common foes. The goal is a swift, decisive victory to maximize points.

• Cyclical Rewards: The spoils of this challenge are essential for our continued voyage, resetting every few weeks to provide consistent trials.

The Maestro's Rewards Table

Why do we subject ourselves to such trials? The rewards are the notes that allow us to compose our own strength. Defeating bosses like the upcoming Sunday yields:

Reward	Primary Use
Stellar Jades 🪙	Acquire Star Rail Passes & Special Passes for the gacha banners.
Credits 💰	The universal currency for transactions and upgrades.
Lost Crystals & Lucent Afterglows ✨	Exchange for precious materials and Light Cones in the Manifest Shop.
Refined Aethers ⚡	Crucial for leveling up character Traces.
Traveler's Guides 📚	Provide character experience to raise our companions' levels.

These resources are the lifeblood of progression, allowing us to strengthen our team, unlock potential, and prepare for the next movement in the cosmos's endless score.

As I stand on the precipice of this update, the impending fight with Sunday feels ordained. His journey from a glimpsed mystery in version 1.6 to an apocalyptic sovereign in 2.6 mirrors our own path—one of unraveling cosmic truths, often through conflict. He is not just another enemy to be bested for Stellar Jades; he is an ideology given form, a philosophical embryo challenging our very purpose. To face him will be to engage in a dialogue written in light, shadow, and shattered dreams. When October arrives, I will step onto that stage, not merely as a Trailblazer seeking reward, but as a participant in a symphony he has orchestrated for our demise or our transcendence. The final note has yet to be written.

This perspective is supported by reporting from GamesIndustry.biz, and it helps frame why a high-profile boss rollout like Sunday/The Great Septimus in Honkai: Star Rail can be positioned as more than a difficulty spike—it's a live-service cadence beat designed to re-engage lapsed players, drive return sessions through cyclical modes like Apocalyptic Shadow, and anchor update marketing around a recognizable narrative figure whose mechanics (multi-phase kit, adds that share HP, and unusual passives) encourage experimentation and roster investment.