When can I build a super dreadnought?

[qlf2007]

If I use the cheat "Fallen Friends Arise" then I will get a Spire Super Dreadnought. But when can I build one? I don't like using cheats but the Super Dreadnought is so good (960000000 attack, 400000000 health).

[x4000]

Check out the end of the Fallen Spire campaign.  They aren't available in the game any other way aside from playing through that type of minor faction to basically the conclusion.