Blackest Night is triggered under the following conditions:
- When 4+ enemies attack your character.
- When 3+ enemies attack your character, no other defensive cooldown is active (Rampart / Dark Mind / Shadow Wall), and HP is below 70%.
Miqobot does not predict tankbusters if this is what your question is about. Triggering Blackest Night in other situations may result in significant DPS loss, because it is not guaranteed to pop. But if you are aware of the incoming damage, you can easily weave Blackest Night into the rotation manually without pausing Miqobot.
If you have ideas for improvement, we are open to feedback.