All Demon Kings.
At the outskirts of Third Heaven System, thousands of spaceships watched in horror as the planet was suddenly engulfed by sea of flames before exploding. The demons seated inside the spaceships shouted in unison.
Even though they were demons, unable to feel empathy and love, they still had something they treasured there. They still had some sort of feelings. Now, it was all gone.
''I-It must have been the work of those vermins!'' A Demon General shouted from command deck. With enraged expression, he pointed into vast space, and shouted, ''Onwards, the battle is awaiting for us!''
However, not even demon joined with the battlecry. Their gazes were still locked on the windows, with destroyed planet donning the scenery...
...
Beelzebub's trembled fist slowly loosened. All of his regret and anger disappeared like a fleeting wind. Then, his eyes widened as he realized what had happened. He turned to a blank space, where a figure appeared, jogging like he was touring through a city.