A = Aggressive; NA = Non-Aggresive; L = Links; S = Detects by Sight; H = Detects by Sound; HP = Detects Low HP; M = Detects Magic; Sc = Follows by Scent; T(S) = True-sight; T(H) = True-hearing JA = Detects job abilities; WS = Detects weaponskills; Z(D) = Asleep in Daytime; Z(N) = Asleep at Nighttime; A(R) = Aggressive to Reive participants
Deathgnash: Resets target's hate and usually attempts to do enough damage to set target's HP to 1, although it can randomly do less damage for no apparent reason. Damage can be reduced to 200 HP remaining via Stoneskin, and as little as 0 damage taken with other buffs, such as a fresh Sentinel. Used in place of Gnash starting at <50% HP. Ignores Utsusemi.
Mayhem Lantern: AoECharm + ~500 AoE damage. Additionally inflicts Shock and bestows an Attack Boost on those charmed. All effects last for approximately 20 seconds. (Not a gaze attack; this attack can still hit players that have turned around.)
Breaking the Nerriviks lantern prevent him to use Mayhem Lantern. Its lantern can be broken by critical hits dealt.
Its lantern seems to break at ~60% HP when fighting it with a pet.
Nerrivik's HP is hidden until his Eye Stalks are Broken.
Ranged damage highly recommended to avoid AoE damage and effects.
It is recommended melee in range have Utsusemi to absorb Seismic Tail, as it can wipe everyone in range without two or more shadows.
Viable strategy: Stun lock Mayhem Lantern and zerg. Critable WS are prefered against Nerrivik. Boost Dex, Impetus, Rogues roll if a COR is available can speed up this phase. Once the lanterns are broken, it's just a zerg fight. Stun locking Nerrivik's TP moves abbreviate the fight as most of his moves are multi enfeebs like Plague, Slow, Para, etc.
Possible failures: it's a plain fight, only danger is a missed stun and having the melee line charmed by Mayhem Lantern. If that ends up happening, mages must run away. If not confident on stunners, make sure to fight in a place free of adds so mages can run away while melees are charmed. Charm doesn't last long.