Add a second Quest portal to a random quest that is not your own role somewhere in the dungeon. The other role’s quest leader and guardians are hostile. You can kill their nemesis but under existing rules, will only be able to pick up the foreign quest artifact if coaligned - which might mean you have an incentive to convert your alignment.

A special case may be needed so that the Rogue and Tourist quests cannot appear in the same game, which would mean it tries to create the Master of Thieves twice.