That's impossible as they don't. It doesn't matter since the Lore tells you everything and, as I've already shown, Algalon's statements confirm it all. They don't do anything on panel because had they actually appeared again, the World would've been wiped clean and reshaped all over again in an instant. Bio's and History are all taken as Canon and fact. You can try and deny what they have been stated as doing all you want, but fact is, it's not changing anything. They are stated as having that kind of power, which means nothing else is needed.
If you really need a visual, then by all means. Here is Sargeras, the fallen Bronze Titan.