The wandering explosive motes in danger missions (and Blades of the Fallen) add a fun little movement challenge, but I've found some of their spawning and destruction behavior to be needlessly frustrating. They always explode and deal damage when they die, which already complicates trying to attack monsters with motes near them, or trying to fire a gun towards allies who may have a mote nearby. This would be fine by itself, but they can spawn unexpectedly, sometimes even right on top of you as you're making an attack. I was killed twice this way doing Heart of Ice this morning when a freeze spirit spawned just as I pressed the button to swing my flourish; with no way to react to it, my sword followed through and popped it, and popped me. I also frequently find them spawning in my line of fire when I shoot a gun, causing an otherwise well-aimed shot to hit "air."

If the spirits did not burst for damage until a short time into their self-initiated explosion sequence, it would reduce some unexpected, unavoidable, and unfun death. The rest of the behavior is probably well enough in line with the challenge they're supposed to provide to remain unchanged.