Bringing back a character I was spitballing a while ago, I ALMOST feel like Livewire VS Surge could work thematically, and give Surge more of an interesting fighting chance since no one can seem to agree where Livewire should scale, so Death Battle's opinion on the matter could be interesting to hear and a bit of a wildcard verdict.
Plus, while Electro VS Livewire is probably overall better in thematics, Surge would be more interesting than just a 'Marvel VS DC who are similar' again.
Female antagonistic-rivals for the main hero, general punk aesthetics, caustic and both act as if its them vs the world, both have electrical powers that they got unnaturally (depending on your Livewire backstory) through the hero's influence (which they both GREATLY exaggerate the blame), honestly just generally blame the blue-goodie two shoes hero for a lot of their problems... I feel like it could be a lot stronger, but I also feel we've had worse thematics to build an episode on.
This is all hinging that Livewire can even hold an episode...Surge I feel is getting there to being able to hold an episode but probably not a headliner yet, still.