Sylvia (シルビア, Shirubia) was a chimera and one of the eight generals of the Demon King, serving as the director of the Monster Enhancement Division. They serve as the primary antagonist of the Konosuba Movie.
Sylvia was a chimera, a creature which could assimilate living creatures and magical items into its physiology to grow stronger, as such a lot of their physiology was artificial. They served as a General in the Demon King's Army and were renowned as having the greatest magical resistance out of the Generals.
Perhaps because of their magical resilience, Sylvia was sent with an army to annihilate the Crimson Demon Clan, a race of genetically modified humans who were highly proficient at magic.
Sylvia and their forces were no match for the Crimson Demons, as, although Sylvia had great magical resilience, their troops did not. Furthermore, although Sylvia was very resilient, they didn't have enough offensive power to deal with the Demons. Eventually Sylvia's objective shifted to obtaining and merging with a weapon sealed within the Village known as the "Mage Killer".
Eventually Sylvia fell for an adventurer by the name of Satou Kazuma, who unwittingly helped them absorb the "Mage Killer". With the "Mage Killer" absorbed, Sylvia transformed into a Lamia-like creature that was completely immune to any form of magical attack, and could spray fire from their mouth.
With this new transformation Sylvia was able to completely destroy the Crimson Demon Village, but was killed by Komekko, who used a special anti-Mage Killer weapon, before they could finish off its inhabitants.
Sylvia had free-flowing bangs that were highlighted red and long, straight hair partially kept up in a bun. Her eyes were purple and they had pointed ears similar to an elf, leading Kazuma to believe she might be some kind of demon.
At first glance, Sylvia appeared as a towering, voluptuous, and beautiful woman. She was so attractive that Kazuma seriously considered defecting to the Demon King's Army to be with her, although this was before he realized that Sylvia was part man.
As a chimera, Sylvia possessed traits typically unique to both males and females. She had the breasts and figure of a woman, which typically lead people to think she was a woman at first glance. However she also had male features which couldn't be picked up on as easily, such as male genitalia.
Sylvia wore a crimson leather one-piece dress made from the skin of low-level devils, white-sleeved gloves, brown stockings, dark-red shoes, a gold necklace and a single blue earring on their right ear. She usually carried a rope around with them to use for the "Bind" skill.
Sylvia was a smart and charismatic leader who seemed to genuinely care about the well-being of their subordinates, often shielding them from the magic of the Crimson Demons. They could be very observant, such as when they deduced that Kazuma wasn't the famed magic swordsman Mitsurugi by noticing the low quality of his blade.
They're quite the seductive type as well, mainly due to the fact that they wanted to seduce Kazuma when he was taken hostage.
They also like to taunt at their enemies and make rude remarks about their strategies and their predicaments. When they're angry, their voice all of a sudden deepens and sounds more masculine.
Sylvia was able to use the Thief skill "Bind", leading Kazuma to speculate that they mainly employed Rogue skills. They were well renowned for their incredible physical and magical resilience, which even the Crimson Demons acknowledged. Furthermore, as a chimera, Sylvia was only part demon, therefore priest magic, no matter how powerful, wasn't fatal to them.
After fusing with the "Mage Killer", Sylvia could breathe fire out of their mouth; although whether this was an ability provided by the "Mage Killer" or a spell they previously knew is unknown. Their already impressive magical resilience was greatly increased when they merged with the "Mage Killer", to the point where even an Explosion spell might not have damaged them.