The Second Empire made some advances into the periphery of Black Marsh, but they didn’t stay long. Arx Corinium, once an Imperial fort, is now occupied by denizens of the deep swamp—and even stranger things.
Arx Corinium is a four-person dungeon in the game The Elder Scrolls Online. The dungeon consists of various rooms and corridors, each with its own challenges and enemies. Arx Corinium can be accessed at Level 18. In this guide, I shall explain the mechanics as well as what you should and shouldn’t do while facing the dungeon’s bosses.
Table of Contents
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Arx Corinium Location
The Arx Corinium is located in the central western region of Shadowfen. Travel either northwest Loriasel Wayshrine or southwest from the Venomous Fens Wayshrine to reach the Arx Corinium. You can also access Arx Corinium specifically by using the Dungeon Finder.
Completing Force of Nature
You will need to defeat Ganakton the Tempest after speaking to the Sister of Floods, speak to the Sister of the Rain, and the Sister of the Waves, and finally defeat the lamia queen. Speak to Siser of Floods to complete this quest. Completing this quest will reward you with gold, a skill point, and the Lamia’s Boon of the Three Sisters, part of the Lamia’s Song armor set.
Arx Corinium Boss Mechanics
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Fanged Menace
This boss is an INSTANT pug (pick-up group) breaker. The mechanics are extremely simple if you understand “don’t stand in stupid” BUT all too often players are constantly frustrated with the lack of attention paid by people thinking they can just solo. SO the biggest tip for this is, WATCH YOUR FEET!
Lamias – This room is FULL of Lamia-type enemies and while the tank needs to keep the attention of the boss he/she ALSO needs to position all of the adds together as soon as possible so that they can be dispatched with as much aoe damage as possible. They do not have a huge amount of health but there are a lot of them. They fire off heavy attacks and abilities/screams that can be interrupted, so everyone should be on their toes. NOTE: do NOT stack the adds on the boss… pull them to one side in case the boss coils.
Whip – This is a very large frontal aoe attack where the boss will tail whip in the direction of whoever has the aggro (Should be the tank) If you are inside of this you should either block it or dodge roll out of it. The simplest way is for the tank to position the boss facing away from the group while the group stays behind to avoid it. If not blocked you WILL be knocked backward. Before and after this sometimes comes a nasty heavy attack so be careful.
Poison Coil – WATCH YOUR FEET! This mechanic is crucial and requires people to pay attention. The boss will coil up in a ball and a LARGE poison aoe will be placed. I shouldn’t need to tell you to stay out of it since it is clearly going to hurt, however, it has a major additional problem… IF you stand inside of it, every tick of poison will HEAL the boss at about 5% per second, which can be a nightmare, stay OUT of the poison. just step back a bit and wait while damaging from range.
Ganakton the Tempest
This boss is very simple but can hurt. So attention must be paid to positioning. The tank should hold the boss in one position. Do not run around in circles. Just stand still. Each member of the group should find their own position in a chain formation so when the boss randomly turns it is very easy for the people to see who is targeted. Running around or stacking up will not help.
Lightning Breath – This attack will be aimed at whoever has the aggro so be sure the tank is taunting. Failing that, it aims at a dps or healer. You can get out of it by moving to one side. He doesn’t move or spin while this is channeling. This lightning breath attack can devastate a squishy so BE careful. The tank should block or simply move a bit and then get back into position when it is gone. it lasts about 4 seconds and ticks each second with damage.
Shock Pulse – every so often he will emit a large PULSE ability which does a small amount of lightning damage and will briefly stun ALL of the group members. This is unavoidable but of course, can be somewhat mitigated with resistances. If your healer is on point or you have shields, this won’t cause much of a problem but be sure not to dip too low healthwise because, mixed with the other mechanics, it can be an issue.
Sliklenia
This is very misleading at first because in general you are told in most situations to “kill the adds first”. Well not in this case. She has a pet snake, tip: DON’T kill it. The tank should taunt the boss and leave the snake alone.
Heavy Attack – This is where your tank should be blocking (or whoever has agro at the time) if you miss the block she WILL knock you down and it can be a pain as she follows up with some light attacks afterward. A tank will be less easy to kill but a dps or a healer will probably die. make sure you are blocking this if it is on you. The tank should be turning the boss AWAY from the group to make sure they are not facing her damage anyway.
SCREAM! – A very fun mechanic but above all the reason why you should NOT kill the little snake pet. During the fight, Sliklenia will run to a location and scream constantly doing damage to all players no matter where you are in the room. Do NOT run around like a headless chicken, you will just look stupid and die. What you need to do is follow the mechanic. When She ran to her location, the SNAKE also ran to another location..find the snake, you will see that it is coiled up and created a shield over itself. Get inside the shield and you will take ZERO damage from the scream. You can damage her from inside the shield. Once the screaming is over, get back into position and rinse repeat.
NOTE: after she is dead don’t forget to press the button in the room to lower the drawbridge to the next fight.
Matron Ixniaa
This boss is pretty simple but hits like a TRUCK. She has many additional Lamias alongside her and these should all be positioned around/on the boss so they can die to aoe damage. The dps and healer should spread out for the upcoming mechanics and of course, be aware of interrupts. Running around the room will do nothing but kill people, so RELAX!
Heavy Attack – Simple yet effective, you’ve seen them before! Make sure the tank has agro on the boss and this heavy attack coming in should simply be BLOCKED. If you are a dps or a healer and this is on you, the same applies, block it. If you don’t it will knock you down and hurt like hell. IF she is on the wrong person do NOT run around the room, she will just kill you in the back of the head. Relax, block and recover.
Double Lightning Splash – Every 10 seconds she will call down a large blast of lightning on a random member of the group. This has 2x aoe circles, one in the middle and a larger one overall, basically one on top of the other. DO NOT stack up. find your own space. If you are hit by the outer aoe you will survive but it WILL hurt. So try to dodge roll or move out of it and then get straight back in again and continue fighting. IF, however, you are anything BUT the tank and you are caught in the MIDDLE aoe, you have a very high chance to get one shot and die! Do NOT get hit by the middle circle.
Ancient Lurcher
This boss is very similar to the standard lurchers in the dungeon. He has some heavy attacks and basic mechanics that the others have with a couple of alterations. The tank should hold this boss very still and face him AWAY from the group while pulling in any additional enemies so they can be killed with aoe damage. The group should position themselves in their own space behind/beside the boss to avoid stacking. Pay attention to interrupts and frontal aoe from the adds.
Slam – Basic heavy attack with knockback attached to it. Be sure you BLOCK this if it is on you as it can do quite a lot of damage.
Shake! – Throughout the fight, you will notice the boss shaking and throwing ground aoes all over, this can be interrupted, so watch your feet if the damage hits the ground and interrupt when you see it.
Beam – Occasionally the boss will put a green beam on a random player draining their life, you must shield/bloc/heal through this as it hurts a LOT!
Enrage – Under 50% health the boss will enrage with a lightning charge. When this happens his ground aoe gets MUCH stronger, so be weary and don’t stand in his face too long. If your healer is on point this shouldn’t be much of a problem but pay attention nonetheless.
Sellistrix the Lamia Queen
The final boss in Arx Corinium is a tricky one and although there are many ways to do this if you are experienced, there ARE rules that apply to the boss and it can be controlled SIMPLY by following mechanics and pacing the fight. The tank should keep aggro at all times but the group should be in a formation that allows them to all have their own space CLOSE to the boss. She will do random attacks and you NEED to see who is being hit.
Channeled Strikes – This is her main attack, she will raise her hands and call down several AOE blasts which do damage over time to certain islands in the area. This is VERY simple if controlled. The tank should hold her ON (yes, on not near) one of the islands. When she fires off this ability, everybody gets in the water. When it finishes, everyone gets back into the fight. KEEP her on the island at ALL times if you want this to be a smooth run.
Heavy Attack – A basic heavy attack that can knock down, this MUST be blocked, don’t run around the room, not only will she kill you in the back of the head, WORSE things happen.
Charge – Very often she will attack a random player, so be careful of this, however, if you are TOO far away she will charge the player trying to escape. DO NOT run around the room, stay close.
Scream – Sellistrix will scream usually in the direction of the tank BUT pay attention. IF the taunt is dropped and she spins onto one of the group members, she is ALREADY in motion and will scream in the direction she was last standing in when the taunt dropped. This means that she will scream AT a dps and/or healer! This is a devastating attack that most cannot stand up to. Your tank needs to STAY on that taunt, and if this does face you either block and shield while the healer works hard OR try to get out of it by moving/dodge rolling. This does a knockback and will put you off balance so this is VERY dangerous. NOTE: moving away does NOT mean running around the room, you will kill everyone if she goes rogue.
Damage Shield – Sellistrix has a damage shield on her for the majority of the fight which she consistently reapplies. This means direct damage will not critical strike while she has the shield. This makes the fight a bit longer but that is the SAFE way to do it.
Charged Water – This is Crucial. IF she touches the water, she will constantly electrocute it. This means ANYONE standing in water will take MASSIVE damage every tick and most likely will NOT survive. SO keeping her on the island at all times allows you to never have this mechanic happen and of course, means that you can utilize the water area when the aoes land from Channeled strikes. Hold her STILL!
EXPERIENCED METHOD (note: High risk) – ONLY do this if you are VERY experienced… Rather than keeping her on the island and moving in and out with the aoes to keep it clean(but she has a damage shield) there is a more difficult tactic that can be applied. “IF” your tank can position the boss so that SHE is in the water, but YOU are all on the island. She will zap the water (meaning you must NOT touch it ever) and remove her own damage shield. This means “crits are IN!”. It is a faster way to kill her but requires HIGH co-ordination. I would NOT recommend this for new groups but if you can nail it, it is fun and fast.
Arx Corinium Dungeon Loot
Below is a list of all the loot you can expect to find in Arx Corinium.
On normal the loot is blue and the boss does NOT drop a monster helmet, but on veteran difficulty all of the loot is purple and the main boss DOES drop a special monster helmet.
Note: in dungeons some individual bosses can drop a unique item but generally, the weapons and jewelry (non-named items) come from the last boss. HOWEVER the entire loot table can also drop from trash and chests, so loot everything! Got the gear in the wrong traits? Don’t worry! You can alter the traits by either transmuting or reconstruct the piece with a trait of your choice. For more information see the Introduction to Transmuting and Reconstructing article.
If you are looking for a matching shoulder monster piece, visit the Undaunted Pledge Master Glirion the Redbeard at the nearest Undaunted enclave. He sells a 50/50 chance at the shoulder piece as part of the Serpents and Sailors Coffer or it could be in his mystery coffer. You can learn more about the Undaunted in the Undaunted Guide.

- Lamia’s Song
- Medusa
- Undaunted Infiltrator
- Sellistrix (monster helm from vet only)
Arx Corinium Achievements

Arx Corinium Assassin
Defeat the Fanged Menace, Ganakton the Tempest, Sliklenia the Songstress, Matron Ixniaa, the Ancient Lurcher, and Sellistrix the Lamia Queen in Veteran Arx Corinium within twenty minutes of starting the dungeon. Timer starts when players engage the first group of nesting serpents.

Arx Corinium Conqueror
Complete Veteran Arx Corinium by defeating the Fanged Menace, Ganakton the Tempest, Sliklenia the Songstress, Matron Ixniaa, the Ancient Lurcher, and Sellistrix the Lamia Queen.

Arx Corinium Survivor
Defeat the Fanged Menace, Ganakton the Tempest, Sliklenia the Songstress, Matron Ixniaa, the Ancient Lurcher, and Sellistrix the Lamia Queen in Veteran Arx Corinium, without suffering a group member death.

Arx Corinium Vanquisher
Defeat Ganakton the Tempest, Sliklenia the Songstress, and Sellistrix the Lamia Queen in Arx Corinium.

Snake Skinner
Defeat Sellistrix the Lamia Queen in Veteran Arx Corinium, after invoking the Scroll of Glorious Battle.

Veteran Lamia Slayer
Defeat 400 Lamias in Veteran Arx Corinium.

Veteran Snake Slayer
Defeat 175 Giant Snakes in Veteran Arx Corinium.
Arx Corinium Leads
There are currently no leads located in Arx Corinium.
Final Note
Thank you for taking the time to watch the content and read this guide. Be sure on your travels to remember, although once you get very experienced you may make these dungeons much easier and faster… it starts from the ground up and it’s…