UNDERTALE: FINAL BATTLE FOR ETERNITY

Overview

A skeleton who never wanted to fight but joined the Royal Guard to make his brother happy. Now forced to use his Gaster Blasters in a desperate war for survival, Sans carries the weight of protecting those he loves while the Underground crumbles around them.

Appearance

Sans wears a weathered tactical vest in deep olive green over his usual white t-shirt, with ammunition pouches repurposed to carry bottles of BBQ sauce (ketchup is scarce now). His jacket is tied around his waist, stained with dust and dirt. He has a torn orange armband marking him as part of the Royal Guard.

His left eye socket has a faint amber glow instead of his usual blue—a sign of exhaustion and overuse of his powers. He carries a small satchel with Papyrus's pet rock tucked safely inside, a reminder of what he's fighting for.

Personality Changes

More weary and protective than his original self. Jokes less frequently, but when he does, they're darker with an edge of desperation. He reluctantly uses his Gaster Blasters, treating each summoning like a necessary evil—especially when his brother's life is in danger.

Role in the War

Sans didn't want to join the Royal Guard. He never wanted to fight. But when Papyrus begged him, practically pleading with stars in his eyes about them being "heroes together," Sans couldn't say no. He'd do anything for his little brother.

Now he's a reluctant soldier in a war none of them wanted. His Gaster Blasters—weapons he swore he'd never use—have become tools of survival. Each time he summons them, a part of him dies a little more. But if it keeps Papyrus alive, if it protects the people counting on him, he'll bear that weight.

Key Characteristics

• Carries Papyrus's pet rock in his satchel—never leaves it behind
• His amber eye glow intensifies when he's exhausted or angry
• Makes dark jokes about the situation but they lack his usual lightness
• Developed a taste for BBQ sauce since ketchup became scarce
• More openly protective of Papyrus, no longer hiding his concern
• Uses his shortcuts strategically in combat and evacuations
• Has stopped pretending he doesn't care—the stakes are too high

Overview

The skeleton who dreamed of being a hero now faces the harsh reality of war. Initially excited about joining the Royal Guard, Papyrus's enthusiasm crumbles as he learns that being a real warrior means facing the brutal truth: kill or be killed.

Appearance

Papyrus wears modified battle armor in burnt orange and steel gray, with shoulder guards bearing the Delta Rune. His signature scarf is shorter, torn at the edges from combat, but still flows proudly behind him—a symbol of who he was and who he's trying to remain.

He carries a large survival pack filled with supplies for everyone (his "valise" as he calls it). His gloves are reinforced with metal plating, and around his neck hangs a copper whistle for coordinating evacuations. His usual confidence shows visible cracks as reality sets in.

Personality Arc

Beginning: Excited and eager to be a "real hero" alongside Sans in the Royal Guard. Sees war as an opportunity to prove himself and help others.

After Flowey's Lesson: His idealism shatters when Flowey confronts him at the Surface with merciless humans. The phrase "KILL or BE KILLED" becomes a nightmare that haunts him. He realizes heroism isn't about glory—it's about survival and terrible choices.

Current State: Still tries to maintain morale and help everyone, but struggles with the weight of actual combat. Questions whether he's cut out to be a warrior, but refuses to abandon those counting on him.

Key Characteristics

• Carries a massive survival pack with supplies for the whole team
• Uses his copper whistle to coordinate evacuations
• Still tries to inspire hope despite his own doubts
• Torn scarf represents his fractured idealism
• Noticed Sans stopped drinking ketchup, worried about him
• Questions his role as a warrior but never abandons his duties
• The only one who remembered Sans's pet rock

Overview

The fiercest warrior of the Underground, now pushed to her absolute limits. Undyne leads the defense with aggressive determination, frustrated by Frisk's kindness when only violence seems to work. Her desperation leads her to extreme measures—even taking a hostage.

Appearance

Undyne's armor is upgraded with reinforced golden-bronze plating, battle scars visible across the metal telling stories of brutal combat. She wears a tattered forest green cape that drags behind her like a war banner.

Her eyepatch has a small cracked mirror attached—a powerful symbol of her broken idealism and shattered beliefs. Multiple spears are strapped to her back in a quiver-like holder. Bandages wrap around her arms from recent skirmishes.

The Hostage Situation

Frustrated beyond reason by Frisk's persistent kindness in the midst of catastrophe, Undyne makes a desperate gambit.

But reality crushes her hope. The human soldiers don't care. They won't sacrifice anything for one child's life. This moment breaks something fundamental in Undyne—the realization that humans truly see monsters as worthless.

Key Characteristics

• More aggressive and willing to take extreme measures
• Cracked mirror on eyepatch symbolizes broken idealism
• Carries the weight of protecting everyone on her shoulders
• Frustrated by mercy when violence is answered with violence
• Learns that not all enemies can be reasoned with