The Chaos Sanctuary is the lair of Diablo himself and the final location in Act 4. Players who seek to destroy Diablo must enter his Sanctuary and open all five seals in order to clear their way to the final battle.
Three of the five seals release a super unique monster: Ghom, Maghda and Iceclaw the Merciless. Once all seals are opened and all super uniques dead, Diablo will be summoned at the central pentagram.
On Hell difficulty, Ghom and Maghda will respectively drop the Key of Sin and the Key of Lies. The former opens a portal to the Realm of Sin and the latter to the Realm of Lies.
