After taking the 3 gifts from the Tentacled Overlord, the process for official induction as a Mana Lord was complete, but Sebastian was not allowed to leave yet as one last procedure was left to be done.
As an official Mana Lord now, Sebastian needed a Mana Lord name.
One of the pinnacle Red tier Mana Lords in the Induction Temple was the one who took on the great responsibility of the naming process.
"From today, under the watching eyes and will of the leader of our Manapedia, the Tentacled Overlord, I hereby name you Mo-bomber!"
…
When Sebastian finally left the Induction Temple, his head was still over the clouds in joy not only due to how much he gained by entering Manapedia but by the meaning of his Mana Lord name that was just explained to him.
Mo-bomber, his new name was a name that was unanimously agreed upon by all the pinnacle Red tier predators under the watch of the Tentacled Overlord.