I think there should be some alerts with stages and waves.
For stages example, the alert could be like the super villain wants to break in to someplace. This is where stage 1 starts, is preventing the super villain and his minions from breaking in. If succeeded, alert ends and the players are rewarded. If failed, then stage 2 happens where you prevent them escaping with the stolen goods. If succeeded, alert ends and players are rewarded. [Optional] If failed, then do some sort of chase. If succeeded, alert ends and players are rewarded. If failed, then alert fails. Of course 2 or maybe 3 stages should be max and each stage timed accordingly, as alerts should still have equal chance of failure.
As for the waves, should be easy to guess, and there could be variety of them and maybe have a limit to 3-4 stages, each with increasing difficulty. Basically it's survival. One wave type could have waves of minions, until you reach the last wave which is the super villain (boss) like for example...zombie survival! Maybe like a zombie horde has broken out in vibora bay and you have to stop waves of them! Then for the boss stage you fight the super villain that was summoning/controlling the horde!
Of course I add limits to the stages because these alerts are usually short/medium length...well shorter than doing like comic series, crisis and adventure packs..which I like about these alerts! They're fast paced and not too long. II. Colosseum/Arena type gameplay
Another system feature could be some sort of Colosseum/Arena style gameplay with different modes to choose from.
One mode could be like where you fight waves of master villains + their minions, and every so often fight mix with super villain + master villains! And you can see how many waves you can go! This can be infinite..well until you run out of super villains lol (that's why the every x levels for the longevity). And maybe if you run out of super villains, then maybe start adding 1 more super villain to the mix (when you reach the super villain level), and keep adding 1 more every so often! (with having 3 total max probably). Also, like instances, you can also have the option to play solo, or queue up a team, and have difficulty settings.
And you can also add another mode to the Arena where you fight 1 vs 1 combat with stages of super villains, until you reach the final stage where you fight the toughest one, like maybe Dr. Destroyer or the Mega Destroid thing. You can start off easy and increase the difficulty each stage. For variety they could be random, or have the option to let the players choose what super villains they want for each stage (with the final still being the same) before they enter the Arena.
Of course, players get rewarded if they beat their previous achievement! III. Player created instances/adventures
Also another feature I saw in a f2p mmo that could of had better potential...is player created dungeons! Basically what it had is, players could choose layout of dungeons, and what mob spawned where...although didn't have alot of depth in its creation.
In champs, players could choose the layout (or maybe create their own if possible lol) and theme for the instance (laboratory, cave, desert, etc) like they can do for their hideout! Maybe also add the option of having the instance 2+ levels (of course, with having a max limit) And they could choose the theme of mobs that spawn in there (like demons, ARGENT, VIPER, cowboy robots etc...) and can also choose the final super villain boss for the instance. For more customization and personal touches, players could add basic stories/mission info for the instance (which you can read at a close-able pop-up window when the instance starts), and change the type of mission. One mission could be like clear out the instance and have the final boss (super villain) appear after clearing it out, and another type of mission where the main goal is to fight the super villain boss (clearing out the instance of the other mobs is optional). Of course, players can have the option of setting the super villain (if applicable) and mobs to the player's created nemesis and his/her nemesis' minions.
Players can play other player's created instances/adventures and rate it!
There could be waaaay more features for this part, but I'm gonna keep a hold of them for now.
I know it's quite a huge post, but I had ideas come in after another, after thinking of one idea! I didn't know whether I should post in one topic or create 3 separate topics. There were no guideline to tell me so, so I just placed all them here, since I also would like to see your guys' comments (if any) all in once place. I tried breaking it down in sections.
I don't know if any of these are possible but I would really love to see these in champs!