Viper (Treasure)
snake
Water 
Shotgun 
Attacker 
Burst 2 
Tetra Tier 3 Snake Sense
Unlocks at: Phase 1
■ Activates when the target appears. Affects all allies.
ATK ▲ 25.98% for 10 sec.
Hit Rate ▲ 11.13% for 10 sec.
■ Only activates when attacking in Vamp status. Affects self.
Sustained Damage ▲ 4.4%, stacks up to 10 time(s) and lasts for 10 sec.
Hit Rate ▲ 1.84%, stacks up to 10 time(s) and lasts for 10 sec.
Snake Scale
Unlocks at: Phase 3
■ Affects self.
Hit Rate ▲ 21.96% continuously.
■ Activates when entering Full Burst. Affects self.
Vamp: Prevents self from being the target of single-target attacks continuously. Loses effect when the caster takes damage.
Invulnerable for 1 sec.
■ Activates when using Burst Skill. Affects all allies.
Re-enter Burst Skill Stage 2.
Snake Bite
Unlocks at: Phase 2
■ Affects 1 designated enemy unit(s).
Deals 1029.6% of final ATK as damage.
■ Activates when the designated enemy unit(s) include the stage target. Affects the same enemy unit(s).
DEF ▼ 19.83% for 10 sec.
Deals 105.3% of final ATK as sustained damage every 1 sec for 10 sec.
Skill recommendations
Build
CUBES
Resilience cube for faster reload. If you get enough max ammo lines, you can also use Bastion.
OL GEAR
Elemental DMG and ATK take priority as usual. Filler lines can be max ammo capacity and hit rate.
Solo Raid Usage
This is based on the top 50 players of all NIKKE servers combined. Data is from enikk.app, check their website for a lot more raid data.
Pros & Cons
- Re-enter burst can be seen as a positive or negative depending on what characters you have invested
- Consistently used on elemental raids since her damage output is pretty good. Worth investing for min maxers that want to optimize the raid damage
- Like all treasures, pretty expensive to build and fully invest considering you need gear, skills and the doll itself
- Skill 2 has really low value considering how expensive it is. You can even leave that at level 1 if you want.