Hello,
I'm playing TERA since 2013, surely like many of you, i'm thinking that TERA was better before but why ? I'll try to go deep in my analyse and i'm also hoping that this post will or can have an impact.
Dungeons are half the answer to why TERA was better before (in some ways) because there are good things now too.
First, i'll speak about my typical top dungeons for me, the coherence between dungeons and quests or univers, then the design about dungeons, and lastly everything concerning lenght, rewards ... Let's go !
- At the beginning, Akasha Hideout was the last dungeon (before Argon War) and i'll take this one as exemple because it's for me one of the best dungeon the game ever had in terms of conception. Akasha have two parts, the first with mobs + a well known little boss but instead of being an annoying/boring mobs basher part it grants different type of ennemies and of course strategies to face against pack of sbire then a strong commander then the teralyth to finish with a mix between monsters letting players deciding to use barrels (could be canons, traps or something to lure mobs). In this first part, challenge is not huge but here still.
- Second part is the most interesting one, there is 4 rooms, 2 with known bosses, Akasha at last AND a special room with an extra boss. The fact there is known bosses at first is important for beginners, they don't have to know the basics of the boss but more special mechanics (the idea, there is no special mechanics in AH). So the main idea is the two first bosses are approachable to reach the last boss. Akasha have also a complete set, some basic mechanics, spawn add, barrels that damage the players if badly used, the boss is not static and dynamic with fast chained attacks (spin>stun>charge) dps or tank have to be careful on each move. Here is the first problem why dungeons now are boring, dps are just spamming their rotation and dodging sometime key mechanics. After Akasha defeated there was two options (dungeon ends or a gate open to an extra boss) and THIS is the key for an interesting dungeon to farm. Dungeons should give a chance to unlock an extra boss, harder more complexe with mechanics but with a better reward (as Saleron with jewels rewards). To finish with Akasha, it's important to speaks about the Hard Mode and the global debuff of this instance. I remember doing achievement when level 60 (max before) with regeant set and i can say that with 10 lvls more and a better equipement it was really hard, of course to do this dungeon we need the potion looted in Golden Labyrinth. This is something missing in dungeons nowadays, a potion that reduce a global instance debuff. Unmissable for beginners, better use for decent players, can be skippable for expert players who want better rewards or score runs.
- Now i said many things about Akasha i would remember you, Wonderholme which was Akasha but enhanced. Wonderholme have everything (except extra boss) i said but put to an higher level. This dungeon use aslo well the raid splitting party with each a different role on the first part, then the clown boss with his epic attack speed buff on time. before Bandersnatch (last boss) we have a challenge area where only the most skilled player defeat a mini boss during others defend the arena. Last boss is also very interesting with a random patern to memorize, poison, global aoe mechanics, and a unique final part. This was the most interesting dungeon for me. And finally, i'll notice Velik Santuary and Forsaken Island for mechanics, each of this dungeon have really great mechanics, they are enough intense to require 100% focus on what happen, with really good paterns on floor.
Now, i'll speak a bit of the coherence and for me on this point the game do well. Scenery are good but lack maybe of magnitude, it's too small. I would like to see something more impressive. For exemple, i can imagine in Wyrmgorge a dungeon with a hill on the back (where is the final boss) spitting fire while fighting bosses aroung alterning with sandstorm switching mechanics like Kelsaik with fire breath to things like area patern like FI with sandstorms. This instance could use the theme of wyrm cemetry fighting bosses, solving a mini-game, splitting the party to solo mini-bosses, everything turning around the main hill where the main boss when defeat could end or colapse the ground for an extra infernal boss in lava where we need a potion (looted from boss before), lava could deal a 'dot' to add an extra challenge like kelsaik debuff. That's my idea :).
All that makes me thing about another problem TERA have now : The content.
The content is mainly focus on high levels because leveling phase is shorten to quickly access at the end. There is reasons about that and i won't discuss about that. So to deal with it, there is few options and for me it's level of difficulty. PvP is also important but it's another topic with a lot of thing to say.
So difficulty needs to be adaptive or some players will stop to play but dungeon needs also to be hard, propose a real challenge (not like GV =_=). The problem we have (we, players) concern the reward, only last boss grant rewards. I would see something more like boss 1 drop a kind of reward, the second another, etc and final boss ONLY important items like gear, masks, maps, emerald/diams but also "prestige points" that can be spend to unlock goodies. For exemple, with 1000 prestige points we could unlock a skin weapon/armor with the theme of the dungeon. Each last boss could drop 4-6 prestige points that could be increased with Tera Club or store potion. These weap/armor skin are on the theme with the instance (water appearence for Bathysmal, or mechanics for RK-9, etc ...). Prestige point could also be use to buy special little buff on the specific dungeon. The idea is to give a goal or another goal to farm dungeons despite of farming enchanting materials.
Miscellaneous
I wanted to notice the dungeon length because it's an important balance to keep. It's really boring to fight a boss with massive HP without a reason. (thinking about 1st boss GV) If the boss have to have massive HP, he also need to have many phases like Bahaar or (i have in mind the Slave Knight or Midir from Dark Souls 3) the boss needs to have great mechanics or intense/rapid attacks to focus the challenge on players stamina.
I mean to have a great dungeon for me, i need to have a dungeon well designed, wide area with interactions between the final boss to give more importance to him. The final boss needs to be impressive or epic like the wonderholme clown or Dakurion's "I WILL CRUSH YOU" with sound bug very high. Shandra Manaya have interaction with quests and buff mobs and mobs buff her there is a lot of ways to explore here. When i think about which boss was the best i usually thing about manaya for teamwork, kelsaik with perma 'dot' + entrance roar, wonderholme clown with speed buff, Valona with the music.
To resume, the dungeons can be improve with :
- Wider space increasing the importance of the final boss
- Adaptive Difficulty with dungeon design (not only NM/HM) with bonus bosses harder
- Special specifics buffs/debuffs
- Better audio
- Better loots division (uncommon only 1st, rare only 2nd, legendary final boss, mythical extra boss or special loot)
- Prestige points for dungeons
Could be perform with two patches :
- Dungeons Prestige Points system with unique buffs and goodies unlockable with it (skins, basic mount, stamp, cards, familiar...)
- A set of new dungeons 3 part-designed (soloable first part to get common/uncommon items, 5-man second part for rare/legendary items + prestige (5 max), extra bosses with random entries/potions immunity condition/key with mythical gear and improved drop + prestige points (8max)
Add 4 new elemental dungeons :
- Bjorndal of Glacial Peak entrance at Forst Reach (south) [Ice]
- Nymphe of Seeliewood Haven entrance at Scythera Fea (North West) [Water]
- Brunildr of the Wyrm Cemetry entrance at Deathgorge, Val Elenium [Wind/Fire]
with a story about the valkyrie queen who killed wyverns there. (5 stars difficulty)
- Dragon Thelodras of Steadfast Grasp at Dragon's Tomb (Serpentis Island) [Earth]
Ice buff that slow movement speed and increase CDR of the party
Water buff that reduce heal from party healer and increase regen the nymphe (final boss) during special phases.
Wind buff increase attack speed of bosses of the dungeon under 25% HP
Fire buff apply a damage over time
Earth buff decrease physical damage
Let me know what you thing about it.
If you have questions or improvements feel free to let a message 
Regards,
