Calus seems to be one of the more prominent characters in the game with his Leviathan hosting 3 raids, one of which where we defeat a robot Calus, and recently we got the Tribute Hall and Menagerie. To me, this is all a gradual build-up to one day fighting the REAL Calus, and, given all of this build up, I really hope that whatever raid eventually features the real him is truly epic. And I don't mean epic as in being over the top with the most complex and difficult mechanics of any raid yet (this raid should be something everyone can hop into and enjoy with FUN as the primary goal, not frustration), I mean epic as in scale/size, and epic in lore. I'm thinking of something like the Menagerie, but on steroids...like the raid by itself will be so big and amazing that it could be reasonably justified as a DLC drop all by itself (okay maybe that's a bit much but you get the idea). The Menagerie is quite a well designed location - the mixture of bright, beautiful architecture, modern, mechanical structures and tech with a touch of darker, Hive-like decay, overgrowth and dirt is really quite cool. The encounters themselves are easy to understand and fun to play as well. If Bungie could take something like this and turn it up to 11 - the visuals, the music, the enemies and encounters - take previous epic activities such as the Whisper quest (and its awesomely dark, hidden, mysterious location), Escalation Protocol and its hoards of enemies and lagged out fights with up to 8 other friends, combine it all and turn it into the raid of all raids...well, it would truly be epic. TLDR: Calus has been built up so much through D2 that whenever we finally get a raid to defeat the REAL Calus, it needs to be the most epic (and fun non-mechanics-heavy) raid we've ever had.