6 Star (Cosmic)

We need 6-star (Cosmic) rarity characters. There, I've said it.

I suppose an entire thread shouldn't be wasted on 2 sentences, so I guess I will expand on my thoughts a little.

I am sure that I am the only one that is annoyed by the fact that Kingpin and Silver Surfer are both 5-stars. Now, I do realize that the number of stars refer to rarity and not power. However, if you take a broad look at the rarities, it is obvious that the more stars a character has, the more powerful they are compared to their less rare peers (i.e. Vulture v. Moonstone) and counterparts (4-star Juggernaut v. 1-star Juggernaut). So greater rarity in the MPQ universe also means greater power.

It can also be argued that there are degrees within each rarity. So some characters in a rarity may be generally more powerful than other characters within that rarity. There are also different strategies and ways to use each character. Some manipulate AP while others hit for major damage. Those are all very valid points, but in the world of Marvel, there is only so much you can do without seriously bolstering or watering down some stats. I will not insist that Marvel characters remain 100% true when applied to all medias, but anyone with some knowledge of the characters should at least be able to look at the match-ups and say "that makes sense." Outside of MPQ, there is a clear winner between Team A (Kingpin, Dare Devil, Yelena Belova) and Team B (Silver Surfer, GE Doom, Apocolypse). Obviously, Team B would win. *Full disclosure: I've never used either of those teams, so more advanced players are likely rolling their eyes at the absurdity of those team-ups.    The point is, short of putting an infinity stone in Kingpin's hand, he should not be anywhere near the same level as Silver Surfer.

With the arguments-slash-counter arguments out of the way...

There are 3 reasons why I think why the inclusion of 6 stars makes sense.

Realism
The first, as noted above, involves introducing slightly more realism to the character levels. Players get really involved when their favorite characters are included. Although Kingpin may be your favorite, having him go toe-to-toe with Silver Surfer feels a little off. Sure, on the surface, it's just a match-3 game with Marvel characters thrown on top of it, but the MPQ team spends a lot of time trying to get the feel of the character abilities in MPQ to match the feel of the character abilities in the Marvel universe. As a result, players get really involved with "their" characters. This is why players get annoyed when "their" character gets nerfed. That character might be an important part of a powerful combo, but just as importantly, that character is one of their favorites. 

Flexibility
Introducing a 6th rarity will allow devs to have greater flexibility in how they create characters. 
Developers/designers of games like MPQ are constantly deciding whether to increase or decrease a stat, impact of an ability, etc. A 6th rarity, gives devs a little more wiggle room to play with.  

Growth
The increasing population of characters will lead to a saturation point where it will become very difficult for future waves of players to obtain the covers they need to build the characters they want. Though the game encourages collecting them all, there are only select characters a player is excited about obtaining and developing. For, example, in my early weeks of play, I only cared about getting 3-star Hulk, Gamora, Dr. Strange and Squirrel Girl (don't judge me). To date, outside of farming, I still don't care much for 3-star Daken, Human Torch, Sentry or The Hood. As I collect 5-star characters and champion my 4-stars, I run into that very issue. There are a lot of 4-star covers out there. As time passes, there will be more, and more of them. 

Adding a 6th rarity will slow this process by pushing back the release of a 4-star in order to release a 6-star. The overall number of 4-star releases will not change, but the pivotal saturation point will be delayed. On the same note, adding an occasional 3-star to the pool would also help. There are people who have been playing this game for many years. As of this writing, I am on my 850th day. I get 25 hero points tomorrow. Woohoo! A 6th rarity is one of those things that will provide bigger and longer term goals for players like me and others who are just starting to play. Not only that, but long time players with championed epics would love to dive into a higher rarity pool of characters.

Finally, a suggestion that almost definitely will not be implemented: Tweak and promote cosmic-like characters to 6-star (Cosmic) rarity. If there was any debate among the MPQ team as to whether a character was too powerful resulting in modifications to water it down, an additional rarity would have helped. If ever there was a character the MPQ team thought was... "epic", but only used that word because it was the highest tier available, an additional rarity would have helped. (At the risk of sounding like the Jeff Foxworthy version of a gamer, I will provide another.) If the MPQ team ever looked at a Marvel character like the Living Tribunal and thought, "we can't squeeze that thing into a 5-star Epic", an additional rarity would have helped.

At this point, there are a few debatable characters that could be 6-star rarity. Again, I know it won't happen, but these are the characters I would like to see tweaked and promoted to 6-star (Cosmic) rarity:
Carnage (Prophet of Knull)
Doctor Doom (God Emperor)
Silver Surfer (Skyrider)
Thanos (The Mad Titan) - he has the freaking infinity gauntlet!!!