Final Fantasy 14 patch 5.5 introduces the Diamond Weapon of Final Fantasy 7 fame as the finale to the Sorrow of Werlyt side story. Like the previous Sorrow of Werlyt trials you’ll have to clear the previous encounters to unlock the latest, but that shouldn’t prove too problematic thanks to the Duty Finder.
Complete Blood of Emerald and In Memory to unlock the quest for the Diamond Weapon Trial The Cloud Deck in Final Fantasy 14.
If you’ve fallen behind on the Sorrow of Werlyt Chronicles of a New Era storyline you can easily unlock the Diamond Weapon trial in a day. The Sorrow of Werlyt doesn’t have all that many side quests between acts, so you’re only true limitation will be the Duty Finder.
To actually unlock the Diamond Weapon trial quest Duty in the Sky with Diamond, you’ll need to clear all of the preceding quests leading up to it. Assuming you maybe skipped Final Fantasy 14 patch 5.4, you’ll need to beat the Emerald Weapon normal trial, which is unlocked via Blood of Emerald. You can grab this from the Resistance Officer in The Lochs (X: 11.3, Y: 22.5). You can queue for the Emerald battle and all the previous Sorrow of Werlyt trials via the Duty Finder.
Once you complete Blood of Emerald speak with the officer again to grab In Memory. Clear this quest to move on to Duty in the Sky with Diamond, which will unlock the normal Diamond Weapon trial, The Cloud Deck. If you want to take down The Cloud Deck (Extreme) you will need to clear the quest that follows Duty in the Sky with Diamond, then speak with the Warmachina Fanatic in The Lochs (X:11.5, Y:22.5).
To enter the normal Diamond Weapon trial, The Cloud Deck, you have to be at least item-level 495 (unless you enter with a full pre-made). If you need to play catch-up the 8-man raid Eden’s Promise no longer has a weekly loot lockout in patch 5.5, so you can farm that alongside Tomestones for updated gear.
The Cloud Deck (Extreme) naturally has a stricter item-level requirement – 510 – so you will most certainly want to farm Eden’s Promise if you want to enter the latest Extreme trial as soon as possible.