Here's a shot of a Mysterious Figure gagging Momo.
Here's a shot of the figure grabbing Momo by the neck.
Here's 4 shots of Nightmare Bot.
 

 

Here's a shot of Nightmare Bot sparking up after the 5 Rangers' "Team Spinning Kick Ball" move. This is what destroys him in Ohranger but it takes a few seconds for him to blow up.