This page explains how to complete the level 80 Endwalker quest "No Good Deed".
This quest is available if you have completed the quest His Park Materials.
Starting the Quest
Talk to Jullus in Garlemald to begin the quest.
Speak with Jullus
Go west and then south to the quest icon on the map. Talk to Jullus to proceed.
Use a Ist Legion Incendiary #37 on the Destroyed Magitek Armor
If you run out of explosives, go to the ❕ exclamation mark and talk to Jullus to get more.
Go to the west side of the orange circle on the map and check on the northernmost Destroyed Magitek Armor. Use a Ist Legion Incendiary #37 on it.
Deliver the Warmachina Ceruleum Tank
Go southeast to the quest icon on the map and talk to Jullus to hand over the Warmachina Ceruleum Tank.
Wait at the Designated Location
Check on the sparkling Destination to proceed. There will be a cutscene.
Speak with Jullus Again
Talk to Jullus to complete the quest.
Next Main Scenario Quest
After you complete the quest, talk to Jullus to accept the next quest: Alea Iacta Est.