This boss, Yllia the Nightbird, is property of The Redundant Button.

Yllia the Nightbird
Boss Info
VRMMORPG Sword Art Online
Location 26th Floor Boss Chamber
Status N/A

«Yllia the Nightbird» is a Floor boss in the game Sword Art Online. She is the final boss of Aincrad's 26th floor.

This boss appears in the fan fiction Misfortune Made Her Sword.


Yllia is a massive creature, standing nearly 3 meters tall even on all fours. She is coloured mostly black, with grey and muted red undertones along her muzzle and hardened underbelly. Despite her name she more closely resembles the bizarre marriage of a bat and a rat than any sort of bird. She has a long rat-like tail, milk-white eyes set beneath large, notched ears and a squashed snout. Her vaguely beak-like mouth and the thick plumage that forms her mane and decorates her shrunken wings are the only indications of avian ancestry.






Like most floor bosses, Yllia sports a total of four health bars.

Despite having wings, Yllia is not capable of flight. Her wings are too small and malformed to keep her airborne for more than a moment or two. She is, however, capable of making large jumps.

Known Attacks:

  • Pendulum Flight - Yllia charges toward a collection of players, snatching one or two up in her fore-talons. They are thrown high into the air and subsequently slapped back down.
  • Back Whip - Yllia lashes out at players concentrated behind her with a wide sweep of her tail.
  • Circle Whip - Triggered when she is surrounded. Yllia shrinks in on herself for a moment before stretching wide and spinning a full circle, striking any player in range with both her tail, wings and talons.
  • Kick - Players located behind her but not easily reached by her tail are slammed with a powerful kick from one of her hind legs.
  • Watch Your Fingers - Players attacking her head are met with frequent bites. Direct hits inflict a large penalty to weapon and armour durability.
  • Hop Skip Scream - Yllia jumps backward with a heave of her wings, damaging any players in her landing area, and follows with a high pitched screech that inflicts a short stun on any players that do not pass a physical resistance check. Players with a high Listening Skill are subject to a longer stun time.
  • Snap Breath - A breath attack triggered only after Yllia's health reaches the half way point. Yllia's chest begins to glow bright red and she climbs the wall of the boss chamber. She positions herself over the largest collection of players and looses a heavy stream of fire onto them.

Item Drops

  • «Nightbird's Hardened Battle-plate» (Heavy Metal Armour)
  • «Nightbird's Talon» (One-Handed Dagger)

Battle Music

Sub Pub Music - Cryogenesis

Sub Pub Music - Cryogenesis

Known Challengers


  • Yllia was originally inspired by the Golden Eagle.
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