Q:

How to reduce rocket tag syndrome for cosmic superheroes?

I GM a MHR game where the heroes are getting quite powerful - we basically have pseudo-Graviton, pseudo-Dr Strange, space-Sunspot, and cyber-Jean Grey. We also used to have japanese-Thor until recently.
This was the point of the campaign, and advertised as such, but recently we are running in a kind of rocket tag issue.
With several d12s on everybody's character sheet, fights can now fall in one of three categories:

Against weaker opponents (d8/d10 power sets): The opponents get stomped into the ground in one or two actions, with low danger for the PCs. This is not really a problem, and more or less what I expected.
Against mobs and/or Large Scale Threats: Although those fights tend to be kind of slow, this feels pretty balanced. It takes a couple rounds to finish, and the PCs struggle and get damaged a bit. I have relied on it a bit recently, and the players are starting to get tired of those.
Against similarly strong opponents (d12 power sets): This is the big problem. Against this kind of opponents, every action is a miss or kill - and with counters, it's more along the lines of kill or get killed. This feels pretty unsatisfactory for everybody, as what should have been epic team fights are generally finished in one round.

As a group, we already nerfed counters (you need to activate an opportunity to counter) and Assets (they step-down on every round after their creation), but this is still a problem, and will keep increasing as characters get stronger (and I don't want to "freeze" them just for my own GMing convenience).
Are there tested ways to reduce "miss or kill" syndrome in fights against d12-powered characters?

A:

Having returned from vacation during which I read a ton of comics, if you're going for genre emulation, here's something to keep in mind:
Superheroic fights in comics are short, so…
In the comics, actual fighting usually really is finished quickly. The majority of an issue is spent investigating, building up the villain, fallout from the villain's scheme, meanwhiles to show simultaneous actions, nonviolent conflicts, and so on. As little as 10% of an issue's panels can be devoted to punching. It's possible that the contemporary superhero film has skewed players' expectations toward a rougher, more combat-centered superhero narrative, but that's a recent (albeit extremely popular) development. Fights, in comics, are often rocket tag. The key then becomes making fights satisfying rocket tag.

An aside: Talk more, fight less
From Daredevil #2 (Feb. 2016):

Daredevil: You want to be part of this world, Blindspot, you need to learn to talk while you fight. We all do it.
Blindspot: My power is being… invisible, Daredevil. Wouldn't that… defeat the purpose?
Daredevil: Powers come and go. Trust me. You don't want to rely on them too heavily. Develop all your skills. Anything can be a weapon. Even words. Trust me on that. (13-14)

(Amusingly, Daredevil's secret identity is as a lawyer, yet you're supposed to trust him. Twice. Anyway.) In other words, roll no dice without first saying something, and adjudicate no result without first saying something else. Obviously, this is an attempt at genre emulation, but it also brings players into the action. If every die roll brings with it explanation, exposition, or exclamation, then you're doing this right, and the combat isn't being artificially extended—it's being extended according to genre conventions. Even the characters that aren't that talkative—Rorschach, for instance, or the Punisher—keep journals of their exploits. Freakin' Wolverine has multiple catchphrases, bub. PCs should embrace this to bring more meaning to what could otherwise be two die rolls and 3½ hours of What now, GM?

(By the way, that issue of Daredevil contains no fights. There's a training sequence with hornhead and his protege, and the bad guys infiltrate a witness's holding cell and chop off a few witness fingers, but no traditional comic book beat-'em-ups. Zero. I picked the issue because of the quotation above, not realizing its lack of combat beforehand.)
…Always give the antagonist a scheme, and…
Only rarely should one thing be happening at a time. If the villain is floating in space, steeled only for confrontation, he'll probably lose but take at least one hero with him. While I suspect there are a handful of cosmically powered entities who could stand up to a sustained barrage from Dr. Strange, Graviton, a Jean Grey that's maybe closer to the Engineer, a Sunspot that's maybe closer to Phoenix, and Thor, that's a pretty tall order if the GM doesn't yearn for the PCs' deaths. (I mean, seriously, that group's got covered, like, the powers of the infinity gems minus the time gem. Although I'm a little disappointed at the lack of Power Cosmic—likely, though, an ersatz Phoenix is close enough.)
That means any individual that comes into conflict with the protagonists must be unimaginably powerful—perhaps Galactus or definitely a deranged Eternity—, or, because it's more fun and plausible, the individual must have a scheme. Further, this scheme must be complicated enough that stopping the antagonist in the ways the PCs have grown used to stopping the antagonist either doesn't impede the scheme or is part of the scheme all along.
This makes the antagonist's defeat only the beginning of the plot. Then, after the antagonist's defeat, the real scheme is revealed, and that scheme requires the PCs to intervene again—often using their powers and skills in unusual and creative ways—to prevent the scheme from reaching fruition… or dealing with the outcome after it has.
…Always make the party worry
I don't encourage splitting the party, although that might happen and it's genre appropriate, but cosmic PCs should be cosmic firefighters not cosmic police officers. The universe is vast, and there should be six impossible problems to handle before breakfast. To paraphrase Aaron Allston in the Strike Force supplement for Champions, 3rd Edition, when events in the campaign are complicated, your job as a superhero campaign gamemaster, is to make things even more complicated.
No antagonist should be hanging out alone in the middle of space, contemplating his navel and considering evil, only to have the PCs roll up on him and kick his space-butt. Instead, an antagonist should be on a space station, threatening thousands, that controls the weather of a planet with a population of billions. And on that space station is the universe's most popular singer who's performing live on Space TV right now. And the planet's made of superexplodium which will destroy the solar system's sun if the weather control device on the space station is damaged. And Spaceknights or the Nova Corps are coming to end the bad guy no matter the cost so the PCs are on a clock. And the antagonist has sought refuge in a conterminous computing dimension inside the space station's omnifunctional weather computer. Did I mention the singer is a PCs boyfriend? He is. And a team of criminals are using the kerfuffle as cover so they can stage a heist? They are. And so on.
In other words, there should always be something else at stake. The antagonist's scheme should always force PCs both to make hard decisions and to be creative. If done well, PCs will often have do both simultaneously.
"Are you sure fights are short?"
Here's Korvac:

Korvac (foreground) travels from the badoon-dominated future to 1978 and downloads into his cyberterminal the contents of Galactus's spaceship therefore gaining the Power Cosmic and becoming, essentially, a god (background). Then…

Iron Man eventually tracks Korvac to a residential neighborhood in Forest Hills Gardens, in Queens, New York. The entire Avengers roster, aided by the heroine Ms. Marvel, and the Guardians of the Galaxy, confront Korvac and [his lover] Carina, who pose as a middle class couple. Korvac's deception is revealed when Starhawk states he cannot see the man called "Michael". Realizing that he has been discovered, and that cosmic entities such as Odin and the Watcher are now aware of his existence, Korvac is forced into battle.
Korvac slays wave after wave of heroes, and is finally caught off guard and weakened by Captain America and Wonder Man. Although able to kill the heroes, Korvac is weakened further by the combined efforts of Starhawk, Iron Man, the Vision and Thor. Sensing that Carina now doubts him, Korvac commits suicide through an act of will. An angered Carina attacks the surviving heroes, but is finally slain by Thor. The entire battle is watched by part-time Avenger Moondragon, who realizes that Korvac only wanted to help mankind, with his dying act being to restore the Avengers and Guardians to life.

(Yes, the 70s were crazy in comics, too.) Emphasis mine, and that emphasized part? Casual slaughter of high-powered folks, some of whom we'd now consider cosmic. For example, Korvac, if memory serves, one-shots both Hercules and the Scarlet Witch. (Admittedly, this is the 1978 Scarlet Witch not the No more mutants Scarlet Witch, but still.) And he murders most of the Avengers (which, at the time, numbered like fifteen) and the original Guardians of the Galaxy over, like, two or three pages. Cosmic fights—when the PCs just bust in on a god hanging out by his pool in suburban Queens—really are rocket tag, even in the comics.
Your job as a gamemaster is to make that possibility as unattractive as possible. Do that by giving the antagonist a scheme and making the party worry.

