Shards! How could we let this happen!

Both the Vorgaltem Citadel and the Crimson Temple have fallen to our enemies!

But we still have one last trick up our sleeve. Lord Marchutan's own exarch, Mastarius, has just arrived and will unleash the wrath of the Shedim Lords...but we need to buy him some time.
If the Vorgaltem Citadel and Crimson Temple are occupied by the Elyos and the Agent Mastarius intervenes personally, your help will be needed.

Ah, that’s not to say you should fight by his side. Of course, that would be a great help, but you should deal with the blessing in Mastarius’s Aether Concentrator so the agent can focus on the battle.
Go to Supplies Quartermaster Cenvezo before heading to the Gelkmaros Defence Base and get the Blessing of Devotion.

Use the Blessing of Devotion in Mastarius’s Aether Concentrator if the Agent Mastarius is attacked by the Elyos.

The Blessing needs to be collected in the Aether Concentrator more than a hundred times for the agent to use the Power Shard. Player, please give the Concentrator more than 10 blessings.
Glory for Asmodae!

I still don't know how we lost the Vorgaltem Citadel and the Crimson Temple, but it's good to know that we have Daevas like you to prevent us from losing Gelkmaros altogether.

I shudder to think what would have happened if you weren't supporting Mastarius. Here, take this--you've earned it and more.