D2 trivia generation for "quiz"

[Crystalion]

Act 4, Chaos Sanctuary when diablo dies. (1)

You are right that someone has to be in CS near/when Diablo dies who gets quest credit, however the other characters in town needing credit for the quest carry-along just fine. So only the Red Portal on Dur3 forces you off your duff (to get to act 4).

In related trivia (e.g. single CDKey rushing without doing Khalims quest) if a char doesn't have/get Council kill quest credit, they can still get out of act 3 but they'd have to visit Trav, Dur 1, Dur 2 as well (in order to bypass the Durance interlock via TP to Trav when stairs down already open, then walking to claim Dur2 WP for use in subsequent game).