Yes, Thor Ragnarok is a fun film that doesn't take itself seriously while demolishing huge swathes of the Thor mythos. There are spoilers galore ahead, as there will be when I finally write up the characters...even though this is mostly about writing up the characters.
This is a movie that moves the scale... so much of it is off the scale. Hela's Strength. Surtur (who is clearly a plot device with a weakness, which Thor takes advantage of at the beginning of the film).
See, when you have these characters in a movie with normal people, then you kinda have to fit them into the range of 8-9-10. Hulk is the strongest one there is, so he's a 10...except Thor generates lightning that knocks him on his butt, and Hela...well, Hela catches and crushes Mjolnir.
Maybe that will get retconned in a later movie as special power that she had over artifacts commissioned by Odin, or she's special because she was the original owner of Mjolnir. Maybe not. But on a normal 1-10 scale, she's probably strength 13 or more (the amped-up Thor is still less than she is). She is just off the scale, and when she gets into Asgard, her power grows (we're told). So Hela might have certain abilities that are just off the scale.
We could just redefine the scale, which you can certainly do: re-define Asgardian nobility as "normal humans" and suddenly Thor becomes a 6, so Hulk is an 8 and Hela is a 10 in Strength...except you don't do bunches of characters like this so they can't interact with characters from other movies...you want them to interact. So redefining the scale doesn't help our ultimate goal of putting all the toys in play. We have to say that she and Surtur are off the scale, or we give them numbers over 10.
For ease of play, I'd probably just say that her Strength is 10, and she has the Quality "Goddess of Death, First-born of Odin" that lets her accomplish things like catching Mjolnir and crushing it.
Her other powers—generating weapons from nowhere (a Slashing/Shooting pair of powers, plus the axe she gives poor Skurge) probably fit into the scale. The giant spike she generates to hold back the spaceship seems to me like a stunt, some kind of Quality like "She and the land are one" being activated and used.
Oddly enough, for a Goddess of Death, she has to use the Eternal Flame to bring the dead back as Minions—she can't just snap her fingers and do it. And I rather expected (with Christopher Yost as one of the scriptwriters) that there'd be some of "every warrior I kill becomes one for my side"...but no.
We probably have to put down a generic Asgardian warrior package, which we can then augment for the Warriors Three. In this movie, they're cannon fodder, but we've seen them in previous films and they're dang good. So your average Asgardian warrior is probably Prowess 5, Coordination 5, Strength 7: Captain America or some other member of the Avengers can out-do them, but they will mow through humans pretty easily. Asgardian nobility are incredibly long-lived, but that doesn't really affect gameplay except when you throw in someone with aging powers.
Whatever that package offers, we up it for Valkyrie: she's strong, her Prowess is high, as high as Thor's or higher, and she's within a point of his Strength, wherever you set it.
Thor swaps out Mjolnir (well, flight, really) for a kick-ass electrical control power that does not seem to include immunity to electricity. (I'm presuming the little control disks are effectively tasers; the jolt they deliver is pretty clearly electricity, so maybe there's a double-talk reason why it works. On the other hand, his lightning fries the Hulk in mid-air, so scientific accuracy isn't at the heart of this film.) When he decides to really be the God of Thunder (well, Lightning), he gets an Aura and some darned powerful Blast...it takes him a turn to re-set his multipower, as it were, but then he's good to go. But that power could be off the scale as well; I choose to believe it was a great roll by Thor's player,
Fenris is probably Growth 9. His main power is being big and intimidating; Growth 9 gives him that and a little space where Hulk can slowly beat him down. (Hmmm. I never thought of Hulk as having Fast Attack, but the thing he does in repeatedly whipping Asgardians around like rag dolls would certainly qualify. Maybe he can only use it when he's established a hold on someone.)
Anyway: when my Thor Ragnarok builds appear, there will be a number of items marked OTS. Hela's off-the-scale powers represent a 15, if you need a number, and Surtur's a 20.
Unless I change my mind by the time I actually write them down.