Hey there. If you're missing it too, it is likely because of the following bug - finishing 'The Invitation' on Legendary will also mark off 'Commencement' on the Legendary triumph, causing players to skip that mission on a Legendary replay, thinking it was done or not needed. Looking at your Warlock's game history, that appears to be the case. A character only qualifies for their exotic once they've finished all 14 missions on Legendary for sure, it is possible to complete the triumph without doing this, but they will not get their exotic until the above is true. So your Warlock needs to play Commencement on Legendary and check the Altar again. As for your team-mate, if it is Bubblehead#3261 who you played most of the missions with, they're likely missing the same mission. If it is not them, please could you share their Bungie Name?