Dahlia is the Special Force leader of the Zeruel dark elven troops and is the boss of Zeruel Border and a mini-boss of Kounat's Collapse. She is a supporter of Ashtaroth's ideals.
Story
Dahlia is first encountered in the Zeruel Border and, like Talin Elfbane, appears to be highly suspicious of the Chase when they first meet and accuses them of teaming up with the dwarves. She then engages them in an incredibly long battle using four different attack forms, but is eventually defeated. Upon her loss, however, Dalia laughs and reveals that she was merely a diversion for Ashtaroth, then teleports away.
She is next seen in the palace of Zeruel, where her true intentions of siding with Baldinar are revealed by the dark elf queen Gilberta. Dahlia then reveals Ashtaroth's plan: he will use the Aernas Hammer again to destroy the world and recreate it in his own image in order to gain God-like powers. She then summons the demon Quoronnos and departs, leaving Gilberta to fend off the beast until the Grand Chase arrive to lend their assistance.
Dahlia once again confronts the Chase in Kounat's Collapse in her cavalier mode, taunting Ronan for failing to save Harpe Noir prior to the events of Monster Train 301. She is once again defeated by the Chase, and Ashtaroth appears and states she no longer has a use for her failure. Dahlia pleads Ashtaroth for another chance, but Ashtaroth kills her and states she can serve by dying. He then uses the remains of her soul to ressurect the Highlanders and uses them to fight the Grand Chase.
Attacks
Dahlia has four different modes, each utilizing a different weapon based on the styles of her subordinates, and thus four different attacking styles.
1st Form

When first encountered, Dahlia is armed with claws, mimicking the style of her Dark Elven Assassins and also summons several of them to assist her.
She can teleport behind her victim and do either a two hit combo or pursue them with a three hit combo from her claws, causing bleeding if the hit connects.
2nd Form

After defeating her in claw mode, Dahlia enters dagger mode and gains Thief-like abilities, movements becoming similar to the Black Wood Scouts and her Dark Elven Scouts.
She has a Rapid Slash-like attack and an attack that involves her leaping up and sending an arc of energy horizontally in front of her. She can also teleport behind her victim and stab them with a poisoned dagger. In this mode Dahlia can turn invisible, though a brief silhouette of her form can still be seen.
3rd Form

In her bow mode, Dahlia's plays evasively and her movements become similar to her Dark Elven Magic Archers.
She can leap up and shoot an arrow down, or leap away and fire an arrow behind her. She can also perform an attack similar to Lire's Metal Shot. Dahlia's arrows incur a chill effect that slows the player's movement speed if they hit.
4th Form

In her cavalier mode, Dahlia rides on her steed and wields a spear and shield and her movements become similar to her Dark Elven Riders. In this mode, attacking her from the front will incur reduced damage as she will defend with her shield.
She is able to do a circular sweep with her lance that will knock up her victims, and can charge forward to impale her victims with her spear. Her steed is also capable of breathing a stream of fire that locks players in its attack.
Appearances
- Zeruel Border (Boss)
- Zeruel (Dialogue)
- Kounat's Collapse
Trivia
- Dahlia is the only boss enemy to have four different forms as opposed to two or three.
- Dahlia is a Jack Of All Trades, having the ability to use claws, daggers, bows, magic, spears, shields, and possibly more. She also knows how to command steeds into battle with her.
- Dahlia is based off the Elsword enemy Chloe. Both are recurring dark elves who had betrayed their own race and aided the demonic forces. Both are also exceptionally skilled in archery, physical combat, and strategic retreat, have used daggers and bows in combat, and have fought the heroes multiple times with more than one form. They also summon a behemoth demon to attack a kingdom and the protagonists.