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 Note: Reive Monsters become aggressive after a player takes one offensive action in Reive. They stay aggressive until all participating players are KO'd simultaneously, clearing all hate lists.
Aqua Blast: Approximately 300-500 physical damage. Wipes Utsusemi. Similar to Hrosshvalur's "ranged attacks", this move is used primarily in the place of Sedna's physical attacks (although both NMs are capable of fitting the occasional physical attack inbetween). This move does not require nor consume Sedna's TP.
Hydro Wave: Light AoE water damage and strips 1 piece of equipment. Temporarily grants Sedna the ability to absorb water damage.
Hydro Blast: Frontal cone AoE water damage and "bubbles" animation effect (Magic Shield for ~90 secs).
The pull may be the trickiest part of the battle. Due to Sedna's enhanced movement speed, it is usually not possible to maintain Sneak while safely pulling it to an area without any Blademaw Pugils, unless you have a means of Flee. Consider using a Sprinter's Drink prior to popping this NM if you have one available.
Alternatively, Sedna can be pulled to the corner to the north, which is a much shorter pull distance and only has the occasional 1-2 Blademaw Pugils that may wander into aggro range.
Striking "!!" weaknesses can be very difficult on this NM due to it nearly always executing some sort of TP move or spell. Though, if TP is not being fed, there is a slight window of time inbetween Aqua Blasts in which trigger attacks can be landed somewhat reliably, similar to the periods inbetween Iron Giant attacks.
Seems to have some sort of hate reset, similar to Hrosshvalur.