I edited. see above.
I'm not actually sure. If you redirect someone coming at you with Mythic force, wouldn't that force be redirected to the new target?
Or, would the act of redirecting it, slow it down too much?
Maybe it could be a second stunt with the first as a pre-requisite?
-1 refresh gets you weapon value only
-2 refresh gets you strength bonus too?
There's an advantage, then, to not taking out the mythically strong person and, instead, using them as a weapon against others...but if you don't attack them and take them out, you're risking being hit by them...
And, if you make it take up your next turn, then you can only do it every second exchange