I agree with you that having one or two extremely overpowered characters at a tier is beneficial for some players. It's mostly beneficial for minmaxers who choose to exclusively play with the most powerful characters in order to win more. These players are massively overrepresented in Line, Reddit, and on this board, but they are by no means a majority of players.
Unfortunately, everything either set of devs have ever done indicates that they do not prefer a metagame where a tier is dominated by the one best character. When there's a best character, they try to make counters to them. And if that doesn't work -- nerf time!
This game exists to sell you roster slots. That's how they make their money. This is why the pace of releases never slows down, and it never can. If every character but one is totally irrelevant, that's really bad for their bottom line (even though it's GREAT for powergamers!) and they've always stepped in to fix it.
It's funny, I guess everyone forgot (or wasn't around?) but we just had this with Bishop. Lots of players now think that Bishop's nerf was universally praised, but that's revisionist -- it wasn't, at all. Tons of lower tier players made the same kinds of arguments about him that are being made about Polaris. "Bishop is intentional -- the devs want to give us a way to punch up!" "Without Bishop nobody could ever move up a tier, he's the only way to achieve X and without him the game would die!"
Well, it turns out that Bishop was an accident (they admitted as much). The stuff he enabled players to do was never stuff they were meant to do. When he was murdered, there was no mass exodus. Players kept playing, and kept moving up tiers. The game was better for it overall.
EB, I essentially agree with everything you say except where you say 'they do not prefer a metagame dominated by 1 character' that only refers to the the highest tier.
In other words, when the 3 star tier was the top tier in the game, nerfs for the 3 star meta were common. Later when the 4 star tier was the top tier in the game, 4 star nerfs were common. Now that the 5 star tier is the top tier, 5 star nerfs (or characters who affect the 5 star tier like Bishop) are common.
We have no evidence of them going back and nerfing characters in bypassed tiers (note, a tweak to a character does not classify as a nerf in my opinion, it has to be an actual nerf to a specific meta) because some meta appeared there (otherwise they would not be releasing OP 3 stars like they are).
That's why Polaris being OP in the 4 star tier doesn't matter. She does not affect roster slot sales in any meaningful way.
KGB
Mod mode off
I also think "the game runs off roster slot sales" is also a little outdated. A load of the cash offers are costumes/ supports/5*. Yeah, I'm sure HP is still purchased for roster slots and other things but I think the game has diversified enough to mean that several different income streams are pursued concurrently.
The evidence for "the game runs off roster slot sales" is past statements from devs, and the fact that the pace of character releases has not ever slowed down.
I have no current evidence of this, but I don't believe the special offers are a big revenue driver for them. It's possible that they are, but they've given us breakdowns of this kind of thing in the past, and roster slots and token packs were always #1 by a mile. Very little money was made on health packs, shields... anything like that. The most purchased item was the $5 HP pack. Maybe things have changed, though.
Remember what the game is like as a relatively new player. The whole "don't open tokens" thing is a bit of advice given from the community -- most players won't see that. Most players will open a ton of tokens, and find that they now have to spend a few bucks to roster their new characters. They might spend or they might quit, but this game is successful precisely because of the constant pressure to spend that's placed on lower-level players.
Anyway I remembered there's a whole article about it! (This was part of a highly illuminating series, the other parts of which seem to have disappeared over the years).
https://venturebeat.com/games/marvel-puzzle-quests-road-to-the-mythical-1-arpdau-part-3-event-design-improvements/
Edit: found the rest!
https://venturebeat.com/business/marvel-puzzle-quests-road-to-the-mythical-1-arpdau-part-1/
https://venturebeat.com/games/marvel-puzzle-quests-road-to-the-mythical-1-arpdau-part-2-cover-store-overhaul/
https://venturebeat.com/games/marvel-puzzle-quests-road-to-the-mythical-1-arpdau-part-4-card-pack-design-and-currency-sales/
https://venturebeat.com/games/marvel-puzzle-quests-road-to-the-mythical-1-arpdau-part-5-adventures-in-consumables/
https://venturebeat.com/business/marvel-puzzle-quests-road-to-the-mythical-1-arpdau-part-6-alliances/
https://venturebeat.com/games/marvel-puzzle-quests-road-to-the-mythical-1-arpdau-part-7-event-analytics/
https://venturebeat.com/business/marvel-puzzle-quests-road-to-the-mythical-1-arpdau-part-8-card-store-overhaul-redux/
@KGB it's true that they've never nerfed a character at a tier below the top tier (that I remember, anyway), but...there's never been a character at a lower tier that outshined her peers in the way Polaris does. So this is all speculation anyway -- you can't say for sure that they won't, and I can't say for sure that they will. There's not really an exact precedent.
I always thought it was pretty unlikely, and then one of the devs posted an offhand comment that put Polaris in the same group as Chasm and Gambit, and well...
I repeat my logic argument here. If they didn't want 4* players to not step into CL10, they wouldn't released kang 3*. If they nerfed polaris because she is really played, if they nerfed SC for the same reason, players would lose A LOT of time and resources and would be really pissed off, because these characters aren't screwing pvp at all, even more they help to move points in pvp.
wow the polaris crusade is real. . Saying she is much stronger than others 4*, and the only way to transition without pain to 5* is an exaggeration.
I am also curious how crusaders suggest to nerf polaris to the ground.