Yes. Make it an escort, set the surrounding group to "rogue." The escort will be hostile to you. If the surrounding group is set to "single" there will be no enemies around the escort, if it is not, there will be enemies, and you will not be able to attack the escort until you defeat them. Make the escort a required objective. Once the required escort dies, mission fails.
If you want them not to fight back you will have to set them to passive, however the passive escort in the Dark Astoria mission would follow you, even though he was hostile, so you could lead him out and complete the mission.
Eva Destruction AR/Fire/Munitions Blaster
Darkfire Avenger DM/SD/Body Scrapper
Arc ID#161629 Freaks, Geeks, and Men in Black
Arc ID#431270 Until the End of the World
Thanks.
To make it so that defeating an entity fails the mission? I'd thought that there was an arc Venture reviewed in which defeating the big bad, who didn't fight back, resulted in mission failed. I'd further remembered/made up someone saying it was due to the entity being an ally set to enemy.
Am I completely missing something, or making something up? Is it possible to have an entity whose defeat by the player ends the mission in failure?
The mission I remember was a theatrical retelling of the Dark Astoria origin story.