I have a few changes I would love to see implemented into CotD. First of all, there needs to be something done about afkers. In my opinion, you can either shorten the timer or add warnings to repeated offenders for possibly short term bans, energy or energy regeneration penalties and/or cancellation of reward streak.
Secondly, I would like to see Megabrawl's energy-to-mbpoints ratio reworked. Rather than 334 Hard brawls, I would like to see more people challenging themselves to do nightmare megabrawls and being better rewarded for a tougher challenge. Also this would ever so slightly cut back on the ridiculously repetitive part of megabrawls.
Lastly, I would enjoy if there was a way to do somethings with the hundreds of duplicates of items just sitting in the stash. If they can be sold for even a little gold or if more nexus combinations added or traded for bronze packs or reduce nexus cooldown timer or something.