Valiona and Theralion

The Dragon Siblings encounter, comprising Valiona and Theralion, make up the second boss encounter in the Bastion of Twilight. They are located in the Twilight Enclave part of the instance and considered a moderately difficult fight, particularly in comparison to the preceding fight, Halfus Wyrmbreaker.

Adventure Guide
''Magically aged to adult-hood, Valiona and Theralion were to be paragons among a new clutch of twilight dragons, leading their brood in scouring Azeroth of life. Instead, they waste their incredible powers constantly bickering and fighting each other.''

Abilities
Valiona and Theralion share an health pool as well as threat. They do not reset upon landing or taking off.

Theralion
When the encounter begins, Theralion immediately takes to the air, while Valiona engages the attackers on the ground. The twin dragons share a single health pool, and each alternates between being airborne and fighting on the ground. Theralion uses the following abilities while on the ground. Theralion uses the following abilities while in the air.
 * Grounded abilities
 * Airborne Abilities
 * Airborne Abilities
 * Airborne Abilities
 * Airborne Abilities
 * Airborne Abilities

Valiona
When the encounter begins, Theralion immediately takes to the air, while Valiona engages the attackers on the ground. The twin dragons share a single health pool, and each alternate between being airborne and fighting on the ground. Valiona uses the following abilities while on the ground. Valiona uses the following abilities while in the air.
 * Grounded Abilities
 * Airborne Abilities
 * Airborne Abilities
 * Airborne Abilities
 * Airborne Abilities
 * Airborne Abilities

Twilight Realm
Being struck by Theralion's Dazzling Destruction or Valiona's Deep Breath pulls players into the Twilight Realm. In this alternate plane of existence, spheres of volatile twilight energy float around and detonate if touched. Collapsing portals appear randomly throughout the area, and players may use a portal to return to the material plane. Each portal disappates after a time. In Heroic Difficulty Shifting Reality also pulls players into the Twilight Realm.

Strategy
When you enter the chamber, Valiona will be on the right and Theralion on the left. Valiona will start out fighting the raid while Theralion flies around, then they switch places periodically and repeat this process for the duration of the fight. Theralion's phase lasts somewhat longer than Valiona's.

Before each transition, the airborne dragon will cast an ability (Dazzling Destruction for Theralion, Deep Breath for Valiona) that transports those afflicted to the Twilight Realm, where Twilight Fiends can be found. Although both abilities can be avoided with relative ease, killing six Twilight Fiends is the objective of the achievement Double Dragon.

The fight has a hard enrage timer of ten minutes.

Valiona
While Valiona is on the ground, positioning is a balancing act between spreading out for Theralion's Twilight Blasts but grouping up to minimize damage taken from Valion'as Blackout. When a party member receives Blackout, everyone can group up close behind the dragon, at which point the healer can safely remove the debuff. The party should then spread back out as quickly as possible.

When Valiona begins to cast Devouring Flames, she will turn to face the direction of the blast. Those within her cone of attack should run through her, or otherwise ensure they are not in front of her in order to avoid the damage. If you find yourself in a bad spot where running through Valiona may take too long, your best bet is to run farther away from her which will reduce the damage devouring flames does to you and may save you.

After two Blackouts, Theralion will cast Dazzling Destruction, which creates two large void zones three separate times in a row that do damage and transport those that stand in them to the Twilight Realm. He will insta-kill anyone left standing here after about 10 seconds. He will then land and Valiona takes off. Another Blackout will come during Dazzling Destruction.

Theralion
During Theralion's phase, people need to group up to absorb the damage from Twilight Meteorite does while strafing to avoid Fabulous Flames and staying out of Deep Breath. Those affected by Engulfing Magic need to run away from the raid and keep healing/attacking, or simply stop any action until the debuff goes away.

There are different approaches to handling this phase, but usually people will mark someone to follow, or possibly split into groups (such as melee and ranged), so you can move together to avoid the fire while minimizing the damage from Twilight Meteorites. Alternatively, the raid can spread out and whoever is affected by Twilight Meteorite can run into the melee group to share the damage. This second method means less movement and potential damage lost due to Engulfing Magic, and requires less coordination, but potentially increases the burden on healers.

After two Engulfing Magics (about 120 seconds), Valiona will take a deep breath and fill one third of the room with flames. She will do this three times to different areas of the room, much like Felmyst in Sunwell Plateau, and the raid needs to move somewhere not affected by Deep Breath each time she begins to cast it. Once she is done, Valiona will land, Theralion will take off, and Phase 1 begins again.

Solo strategy
If going for the Double Dragon achievement, begin the encounter and then stand still until the phase transition. Make sure to stand in the area of effect to transition to the shadow realm. Once on the other side, stand in the center of the room and turn on V-key health plates. Adds are small and hard to make out in the ground clutter, so the health bars will help. They barely have 10,000 health, so use quick attacks to finish them off. The achievement will be awarded the instant the sixth has been killed.

Once done, just blow up the dragons. None of the abilities hit particularly hard.

Related achievements

 * The Bastion of Twilight (achievement)
 * The Bastion of Twilight Guild Run
 * Heroic: Valiona and Theralion
 * Double Dragon

Quotes

 * Intro
 * yell
 * yell
 * yell
 * yell
 * yell

Theralion

 * Dazzling Destruction
 * yell
 * yell


 * Killing a player
 * yell


 * Engulfing Magic
 * yell
 * emote


 * Death
 * yell

Valiona

 * Blackout
 * yell


 * Deep Breath
 * yell


 * Killing a player
 * yell


 * Death
 * yell

Outro

 * yell