Nihilister

A Fire B2 Sniper Rifle DPS whose strengths are Full Charge Pierce and Burst Gauge generation.
She is weak as main damage for story and bosses, and is used when conditions fit in Pilgrim Tower and fast-Burst Arena teams.

Burning Shot1 grants a Pierce bonus and expanded pierce range to 1 shot each Full Charge, and hitting 2 or more enemies with one shot deals extra damage. Megiddo Flame2 is her S2, dealing damage to enemies in range every 10 seconds. Burning ScourgeB applies area damage, burn damage over time, and Increased Max Ammunition Capacity for herself.

Her Burst cooldown is 20 seconds, and Nihilister is the only 20-second-cooldown B2 in the game. As a Sniper Rifle, her own raw damage is lower than other B2 and B3 DPS.

Land one Full Charge shot on the core or clustered enemies to trigger Burning Shot1's Pierce and multi-hit.
Use Megiddo Flame2 within range whenever its cooldown comes back.
Auto is basically fine, but aim manually for Pierce and hitting 2 or more enemies.

There are almost no fixed pairings frequently seen in recent top Raid and Solo Raid teams. In Pilgrim Tower she is often fielded alone when a 20-second B2 is needed, and in Arena she fills a B2 slot that charges Burst quickly.

For Full Charge tempo, prioritize Adjutant Cube; for Pierce damage, Piercing Cube. For Arena, Quantum Cube is the next option. If Harmony Cube levels differ a lot, use the higher-level cube before following the ranking.

As a Sniper Rifle Charge weapon, set Charge Damage and Charge Speed lines. Supplement remaining lines with Hit Rate, crit, and ATK. Max Ammo overlaps with Burning ScourgeB, so keep it low priority.

If you have no plans to use her, leave her at 1/1/1. When raising, bring S1 with Pierce and multi-hit and S2 Megiddo Flame2 up first; Burning ScourgeB can stop around 4.

Mainly fielded in Pilgrim Tower when a 20-second B2 is needed. In Arena, used as a B2 in fast Burst Gauge teams. Rarely used as main damage in general story, bosses, or Raids.

Each Full Charge adds a Pierce bonus, helping with parts and clustered enemies.
Despite being a Sniper Rifle, her Burst Gauge generation is fairly fast.
As a 20-second-cooldown B2, she meets Pilgrim Tower team requirements.

Her own damage is lower than other B2 and B3 DPS.
Burning ScourgeB's burn and instant damage contribute little.
In general PvE, recent B2 alternatives outclass her, so she is rarely a core pick.