You know thinkin about it i'd hav made trip into Baator like lower levels o first Diablo, some infernal stronghold on Carceri, that you hav to sneak round an survive while witnessin all sufferin an punishments being meted out to souls. Outside you could hav entire Blood War ragin, little cutscene showin somethin like end movie when you look out window. Chat wi tortured souls, see structured cruelty of Baatezu at play, maybe even hear the roared commands of a Pit Fiend echoing through corridors. Spikes holding quivering corpses that despite whatever limb is missing still live, a constant moaning of damned souls, gargoyles an decorations that have a kind o half life an lash out at anyone passin by, sudden explosions o fire an magma as ground splits apart. Could even bump into Athelgrin an Tegarin again maybe, specially wi that Pendant o Yemeth quest now back in game?
An as you infiltrate deeper into heart o citadel you hear the gibbering of the Pillar o Skulls, the heart o this stronghold, what its been built around.
Take a fair bit o work an resources I imagine though.
Could hav Grace bumpin into somebody she knew once when held by Baatezu, see maybe old chambers o Fhjull Forked Tongue an find out more about his pacts, maybe even see a Paladin in Hell chained an bound by the evil that holds him hear an despair that is stronger than chains, maybe some old remembrances o Trias when he came to bargain wi Fhjull? Could make another hub, more civilised an urbane than Hive, but even more dangerous for soul an body, wi plenty o opportunities to make bargains an pacts. Be real nice to sell Tome o Pestilential Thought to an infernal merchant, the book betrayed for once instead o other way round.