And then again here:

Keep the Fortress open after the event.

Don't go through with this absurdly stupid idea of removing content from the game for no discernible reason whatsoever.

Hey, does anyone know how to get the barrier buster achievement shown on the event overview? I have the other three showing complete (caltrops, pet, and whatever the fourth on was).

I finished the helping skodo quest, completed the fortress and turned it in back at the camp and it’s no longer in my journal under quests. The barrier buster achievement and momento still shows unachieved.

After playing all 3 parts of the event, I want more things like that. But there were cons.

+ Daily quests fit for at least 2 activities (crafting and killing mobs) were good.
+ Phase two surprised crafters with a bit more variety, and that was good too.
+ I especially love the variety of locations available for kill-n-loot quests. Being able to do every quest in a new zone by choice has made it way better than doing the New Life event quests for example.
+ Changes in lens effects were just necessary, and they were on place. Watching that something is slightly changes was a special kind of slow fun
- 40+ days was grindy, really grindy. I know, it is about letting all the players participate, but well it was close to exhausting.
- Having haj mota parts instead of bone shards in box loot is irritating. It should've been cut by the achievement (collected haj mota - no parts of it until the caltrops style is collected) or divided among quests (lenz give shards, mats give mota for example), but not like that. Just check the prices of bones and mota parts on guild traders to see the difference in amount supplied.
- Blocking the Undaunted (Bolgrul) quests with daedra resp is a wrong solution. Some new chapter event shouldn't block a daily routine for non-participating players for a month. It is totally wrong. At least make the daedra resp 1 of 2 times, so players could kill their delve boss after 2-3 attempts, but don't block the progress. If you want to block it, then block the Bolgrul too, make him say that all the Undaunted went to Stirk or whatever. The current way is not a solution but a gameplay bug.
-/+ Souls and mats drop for daily quest was horrible at start. Thank you for fixing it on fly.

+ Siege camps mechanic is nice. It distributes the players on the first step, if there are too many participants, and concentrates them on the final step. At the same time, it allows killing mobs group by group doing it solo without being overwhelmed. It is a great solution after W-Skyrim world event problems. Thank you!
+ Styles, recipes etc in the list of world event rewards are cool.
+ Bosses are challenging but doable. I was glad to see good old friends from the imperial sewers among the besiegers. Has that two-hand swordsman resigned? I miss him
+ Two bosses in the central camp is an interesting solution. I'm not sure if it is a good idea for after-event rotation, but I like it at the moment.
- Souls drop from the camp mobs is still unobvious or buggy. I can obtain zero souls from 4 waves I killed solo, but if I manage to use that shred pinion I will have souls from mobs I didn't even touch (I'm not in a group).

+ Fortress encounters are great. I wish to run that kind of trial for 12 players. Shoot a boss with ballistas, split the group to open the way to each other, bring ballista ammo for friend... That was cool! Please make it a real trial.
+ While I barely like the coldharbour style, the design of the fortress is nice. Please pass my love to the designers of the final chamber after the titan battle. Those Giger-like vibes warmed the oldman's heart
+ The connection between the low and high paths that allows players to jump down or jump up is a great solution. That allows the instance to be soloable (if somebody has to), which is good.
+ I'm glad to see Vateshran mechanics back in the game. Maelstrom ones in the dungeon... Now this... Sweet nostalgia. Thank you!
- Joining the run in the middle is just painful. Yes, it enforces those few who started it in a small amount... but it makes the full run like just a lucky coincidence. It is not fair. Please give me an option to choose between a full run or joining in the middle maybe?
- It is buggy. At least two places have bugs that block the progress. Yes, I know it is very dynamic, and so many players, and so on. But please test it. I jumped in tens of instances during the day and about a half times I ended up in the bugged ones. Some players just sit there and moan in a zone in despair. There is no such thing that kills the fun more than a blocking progress bug.
- The protection ball mechanic is not explained well enough. You can see the Vateshran veterans from the start, yes. But many players just avoid the plasm or die there with no clue how to manage it. I don't know a good way to do it: make an npc eat those red berries or something else. Just a fact - it is not clear enough for players. Not like shoot-n-pull.

+ Stirk quests as a way to participate aside of Solstice - it is just great. Well, it is even more grindy than Solstice. You can not see any progress but the progress bar on the web page. Anyway, players got their quests, their loot and their fun. It is way better than any previous chapter event.
- Stirk players kill two delve-boss-difficulty mobs and get the crown. Wait, what?! We worked on ballistas till our palms bled, my friends have fallen dead to the lake of dirty plasm, we fought for each meter of that fortress against countless daedra to get this crown! Now that guy got the same for delve-like quest. Omg!

-/+ Ghishzor, who is it? I heard something about it, but didn't meet it neither in besieged camps nor in the fortress. Probably it is some kind of scary tale for the magical Argonians? Jokes off, really, this boss is totally cut from the event. While the battle was fun, the boss as it is should've been integrated better.

Wanted to wait til the wall was overall done to give my feedback so here it is.

For positive stuff I don't have much but I still want to put out that I like the idea of zos trying new things and shaking things up, even if those things don't succeed. Trying new things keeps the game from getting stale, even if some of those things flop. The Writhing Fortress part of the event is beautiful and interesting overall and the part of this I enjoyed the most (second place going to free extra craft loot a day). While I did not like the execution, I also think there is room for multiphase events in eso in the future if they are done differently and I would not mine seeing them (could even test the waters for giving zones proper weather/seasonal systems down the line and making it feel more lived in?).

Now for the negative, which some has been said by others and some has not. Gonna break it into parts/pain points:

• Expectations vs Reality and Flawed Design-I don't know if the people who made the event are out of touch with the community or miscommunicated, but this event was extremely hyped up and did not deliver, but also seemed to do things that players have either explicitly or implicitly expressed they did not want to see in game for years.I know other mmos have them, but part of the appeal of eso for me is that the content is always there to play at your pace story/lore wise. I can take a break for a month or a year like I have in the past and return with everything waiting for me to continue. I specifically play eso over other mmos because I don't like gated exclusive content and the like. Similarly, ESO has had a strong marketing of #ESOFAM for years and a focus on community and togetherness. All prior fall events were collaborative, but this one was suddenly competitive. It feels like whoever was pushing this was either testing the waters on future things (which if so, most of us don't want these, it's not that kind of game) or did not understand these would go poorly. It did not help early frustrations on design that the race seemed heavily skewed and was adjusted multiple times to achieve certain results in a way that made it feel unfair/meaningless on who did what first.
• Reward vs Punishment-The event's reward structure missed the mark. u48 coming along and having nothing to do patch day vs the usual patch day account management and a handful of leads felt very bad. Many players, myself included, felt like we couldn't play the content we played for because of this event. It did not help that most of the daily event quests were buggy or felt like chores, making the wait for Eastern Solstice feel more bitter. I had a lot of friends and guildies comment on burnout and frustration with the event boxes as per point one, they were playing the Writhing Wall like every event prior to it in recent history that has a specific system of loot expectation and not getting the results they had come to know.
• Bugs-I know bugs are inevitable, but a limited event will fall under far more scrutiny and this event had many unacceptable bugs for limited content. From fetch quest droprate to entire instances having mobs disappearing, these are not nearly as funny or acceptable when the content is on a time limit or gating progress. I also am angry about two bugs in particular that unlike the more popular ones got no ZOS feedback. We asked you multiple times in multiple threads about Watcher Zvarbin and Scamp Champion Doov's bugged spawning with no answer. We also have had multiple issues with lorebooks tied to this event and one was fixed if you abandoned the quest and restarted it while the other seems to be unobtainable currently by anyone who has the seasonal pass. We already have expressed frustration with books that have been bugged for years in multiple threads and the fact these books are tied to limited event quests is extra frustrating. I wanted to focus on these two bugs because I did not want to retread ground with other posters but also to say some bugs have been ignored entirely where even a word of "we're aware" would have been nice. I also think especially because it's temporary, the Writhing Wall being as buggy as it is for so many is a massive problem.
• Clarity-This event's information and communication has sometimes been confusing and contradictory. As I stated above, there were things not ever acknowledged, there has been some general confusion on how the event operates and what is permanent vs temporary, and other general confusion. While zos has gotten better at communicating than in prior years, they also need to continue to work a ton on communication and transparency. This event, by design or by bugs or by overhyping or a few other things has broken a lot of people's trust. Trust is something that needs to be built up. As I've come to the forums to check on bugs/info for the Writhing Wall and from talking to friends and guildies, a lot of people are wary about next year's content due to how poorly this event landed. It would be appreciated to have at least some sort of post-wall comment from zos given how this event landed and how it ended up going for a lot of people. I know some people enjoyed the event but most I personally saw did not, and while at times I saw the vision, I too did not find this event overly enjoyable.

Again, didn't want it to be super negative but there were a few things I needed to get off my chest about this event.

Please fix PS EU - the infernium doesn't goes to the gate making it impossible to reach the boss (left side)