Who is the most powerful Character across all of the blizzard universes?

[Edge-]

Thrall, because Metzen would bullshit him some crazy power to defeat anything that might threaten him.

[Mormolyce]

Whoever is running Heroes of the Storm.

My money is on the dark voice from Starcraft, but we don't know the full extent of its power yet so...

Are you talking about the Dark Voice or the Voice in the Darkness? They're different, because thanks spinoff lore.

I'd say either Anu or Tathamet from Diablo.

It is unclear whether Anu is a real entity or just an origin myth in the context of the Diablo universe.

If he ever existed, he's probably dead, like Tathamet is.

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Thrall, because Metzen would bullshit him some crazy power to defeat anything that might threaten him.

Why not Varian?

You know Metzen voices him too right?

[derpkitteh]

if there's a true god/goddess of warcraft, that's probably it. if not, probably the titans and sargeras. i don't believe there's anything in star craft that can really match them. the angels in diablo may be close though, but i don't think they're quite to that level. the titans are capable of creating and destroying entire planetary systems in the time it takes a heart to beat once, that's pretty damn close to being gods, and it's assumed that sargeras has only gotten stronger.

[Arbs]

Tassadar, my personal opinion. Diablo a strong 2nd.