Vinsomer

Vinsomer is a high dragon in Dragon Age: Inquisition. This dragon is encountered on Dragon Island; the western area of the Storm Coast. Vinsomer's stats are as follows:
 * Level 19
 * 226288 HP (Nightmare difficulty)
 * 59 Armor
 * Greater Electricity Resistance
 * Spirit Vulnerability
 * Immunity: All Disabling Effects
 * Immunity: Slowed
 * Perceptive

Dragon Island
In order to reach Dragon Island, the Red Water quest must be completed.

Description
Vinsomer "breathes" electricity instead of fire, dealing electricity damage. It is therefore resistant to electricity damage, but vulnerable to spirit. Its methods of attack are similar to most other dragons, but its unique skill is a mobile version of Static Cage that becomes "attached" to each party member with a damage-over-time effect dealing electricity-based damage every 3-4 seconds for 20 seconds. Any character that crosses within the field of another receives increased damage which stacks.

Strategy
Offensive
 * Characters with high Guard Damage Bonus, from skills or weapons, are needed (preferably Warriors).
 * The use of Spirit Runes will aid in exploiting the dragon's weakness, though Dragon Runes are a better substitute, in general, for dragon hunting.
 * Mages should use staves with any element type other than Electricity-based damage.

Defensive
 * Dispel removes the Static Cage effect from party members. Note that the damage from Static Cage can interrupt the casting of Dispel, so timing is important.
 * Electricity Resistance Tonics can prove useful throughout the battle.
 * Warriors with the Shield Wall talent can absorb most damage inflicted as long as Stamina is sufficient.

Rewards

 * 3000 Influence
 * 4 Power
 * 1 Master Dragon-Slaying Rune (Schematic)
 * 1 Dragon Gland
 * 4-5 Pure Dragon Blood
 * 1-3 Dragon's Tooth
 * 6-10 Dragon Webbing
 * 6-9 Dragon Scales
 * 7-10 Dragon Bone
 * 6-10 Dragon Webbing
 * 6-9 Dragon Scales
 * 7-10 Dragon Bone