So 2.5 years ago I wrote most of this, still be nice to have if you're interested.
IF I had to choose, I would say level 50 guilds and New Leagues up to 20K or more

New Features
- Tournament star calculator to make dreads more competitive (Try higher the DCR the more stars you get)
- Level 50 guilds
- Leagues up to 20K Trophy
- The ability to rename guilds
- Banning players from the guild
- Better search for guilds
- Make it more expensive to start a guild, maybe 100 dread stones or 500 gems
- Notifications when someone is at the guild door, same as how you do it when someone has typed a message
- Stop the leader leaving the guild by accident. They Must pass leadership before they can leave the guild
- Open Locked or Closed guilds if the leader is inactive for 30 days
- Improve Dragons and ghosts so we can use them
- Give us more leader boards so we can compete against each other (best win streak would be nice)
- Give us more guild keeper statistics that don’t disappear when you leave a guild
- Redesign your dungeon quickly, a button that digs out all available squares
- Introduce some new guild banners
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Bug fixes
- Black bits in immortal training and scrolling in achievements
- Fix the 30 min Kick outs from the game
- Fix the immortal selection where you select an immortal and the game restarts
- Clean the leader board of the cheaters
- Fix the plunder leader board
- Trolls attacking air
- Training timer fixed
Bugs from 6.0
- Ability to disable room badges in attack mode
- Disable trap glow area too big, return to how it was previously
- Removal of the hex values from players names now shows an indentation when attacking them. Remove the indentation
- Keepers who have now completed the campaign should have their names shown in Gold in the guild too