This is a screen shot of us before we even found the end fight, having killed all the monsters we came across along the way:
and..
For educational purposes, we learn from these images that Conquest is between 471 and 479 kills. We were at 550 kills before reaching the end fight. Coincidentally, this was also our attempt at a ~45 minute speed run which apparently went as bad as it could get.
In the above, some newb member of our group claimed to have "accidentally" activated an Orb when engaging in conversation with Ana. The result? A Minotaur spawning in a pillar that we couldn't destroy, rendering the optional objective impossible to complete. At this point, I believe the hand hadn't spawn.
Ana decided to walk off the edge along the way and get herself trapped at a spawn location. I was forced to jump off until I caught her before she could de-spawn. The hand spawned at this point if memory serves, but both variables were eliminated at about the same time.