User blog comment:Crimson and Darkness/Volume 24 discussion blog/@comment-28626666-20180102035032/@comment-1359322-20180102063620

Since Mephisto existed at the same time as the original Maous, i doubt Lucifer created Beelzebub etc. Probably Devils existed prior but their numbers were low and maybe even weak. So Lucifer tried to create more powerful Devils and was successful.