Nightmare campaign is late game but not endgame. An arena rework is coming soon and will hoprfuly fix current issues, so please stay tuned. 

Yep, the Arena rework is on the way. You'll get more details later

Also, I would like to encourage you to check out for existing threads that cover your topic before creating a new one. This makes the discussion more focused and the feedback collection more efficient. Overall it makes communication between developers and player audience faster.

There is communication between developers and player audience? hmm...only indirect communication I guess?

I'm almost at 230 days of play and I was progressing steadily until 6 weeks ago when suddenly the "bots" or ancient players were removed from the Arena. Result Gold 4 to silver 4 and a descent into hell that continues as all the teams that are offered to me are still far above mine.

As a result, I'm stuck for more than a month on the progress mission "reach gold rank 3 in arena" and therefore unable to finish this part of the game and finally get Arbiter.

I used to love this game and so I used to enjoy buying packs sometimes. Now I just want to stop. Tiring to try to get new characters and boost them to the max with no effect on my progress in the game.

I understand that the bots may have made it too easy to get to the top levels, in which case it would have been smart enough to create new top level for Arena. No way u should take back what you gave away for a while. If you don't reward players who invest time in the game beyond their simple level, then you create frustration and this is rarely a good method to generate revenue. 

Seeing a lot of clans slowly emptying and considering merging, Plarium needs to act fast. Personally, I won't wait another month. I don't pay to expect to win when I only lose, I pay if I enjoy the game. Too bad Plarium doesn't understand that or perhaps they just don't need our money...

I don't know to what extent you all communicate internally, but I was told to come discuss it on the forums when I first raised the issue of the arena through the in game support.  Later when I raised it again, I had an email exchange where I mentioned  a post in this forum where a player said that player power determined matchups and the plarium employee told me that player power has very little effect on matchmaking in bronze and silver.  2 days later plarium admitted that player power was an important aspect of their matchmaking algorithm (which is just an odd decision in my mind since account power doesn't determine individual team power at all and "power" as defined in game is a very bad substitute for actual in-game power).  If someone new comes here and creates a thread, there is a decent chance that they don't want to read through every post and were just trying to register their strong feelings on the subject in  the only way that a plarium employee told them to.  I'm sure it is frustrating to moderate, but the feelings of player frustration are real on the subject.  

The speed meta is what is breaking arena.  They need to realize that not everyone wants to gimp 3 teams of their best champions just to compete in tag team arena.  

In the main arena neary 75% of the teams seem to have an Arbiter lead.  I have a 218 power team and I am consitantly beaten by 2 champion teams with Arbiter and a strong nuker.  Having Arbiter and Ma'Shalled is all a player needs to beat most teams.

To complete my dailies I spend between 70-200 gems just to come up with 5 teams I am sure I can compete against.  Just the shear numbers of Arbiter leads should have shown Plarium arena is broken.  I'm becoming more and more disillusioned with the game.   And for me at least, disillusioned is soon followed by not spending and then not playing. 

I  feel  like  i  am  running  into  a  lot  of  split  teams  with  low  power  but  a  mix  of  50s  and  60s

I  just  battled a  level  50  MM  in  areana  that  was  like  a  brick  wall  for  my  team  of  60s.      Gear  seems  to  be  a  huge  factor  as  it  should  be  but  it  seems  like  a  50  should  be  a  bit  squishy  when  fighting  60s.      This  MM  definitely  was  not.

I have no worries about Arbiter, but what gets me upset is that I can never get other champs I would rather have much sooner, to let me know that Plarium has not stuck a knife in my ID and blacklisted me from ever getting anything but junk category rares.  I see so many other folks having these as common as water : the Witch, the Monster, Gorgo, Skullcrown, etc.  I will NEVER get a shard lego from this game, but at least some good epics or rares would be nice.  And don't tell me I already have something good in my vault but just don't realize it, been there done that. I cannot believe  the amount of junk that Plarium wastes effort to make to shove them on people.  How is that supposed to keep people engaged in the game?

If it's just another matchmaking tweak, you're going to go back to square one in a week or two.

Seeing  a  trend  in  b3

level  40/50  buffers  with  a  monster  60  nuker....keeps  the  team  power down...easy  enough  to  spot  if  you  are  looking  for   it  but  its  a  trap team,  and  40 boosters  with  an  60  needs  limits  IMO