|Part of an official artwork (along with her two sisters)|
|Title:||Blue Dvalinn; Blue Sister (Durathror)|
|First appearance:||Boktai 2: Solar Boy Django|
|Voice actor:||Donna Burke|
Blue Dvalinn (ドヴァリン) is the Sea-Ruling Immortal, eldest of the three Immortal sisters, and a member of the Shadow Clan of Immortals. Dvalinn was sealed in San Miguel's Aqueduct until released by Black Dainn. Although she was weaker like Duneyrr because of the time she was sealed, she used Octopodes to gather energy. She fights against Django and is defeated.
Dvalinn has the ability to assume the form of an octopus to fight. As a octopus, she attacks with her tentacles to slam enemies and throw rocks, spew ink balls, bubble Breath and Dark Breath.
- Dvalinn's weakness is Flame.
- Dvalinn normally stays out of reach for most of your weapons, so bring a good Spear to the fight.
- If Dvalinn appears up close to stun you, the attack can be cancelled either with a Flame-enchanted attack or Dynamite.
- Change Bat also helps in avoiding the stun attack.
Dvalinn and her siblings are named after Dáinn, Dvalinn, Duneyrr and Duraþrór, the four stags of Yggdrasill, who live in its branches, eating its leaves.