The Glory Days - Devilgram
"I want to beat Diavol..."
There was a ceremony prepared for the visitor of the Celestial Realm. Lucifer wasn't told about it by his Father, but he pretends to know. Still, he is annoyed that his Father didn't tell him this either. However, he has no problem with coming up with a speech on the spot. Afterwards, in Diavolo's castle, he is complimented more by Diavolo while they play chess. While they talk about Diavolo's dream, it looks like Lucifer is winning, but he realizes he is actually losing. Lucifer shakes Diavolo's hand for the first time with respect.
Back in the present, Diavolo tells Lucifer that he still remembers it as if it was yesterday. He thought Lucifer had a truly beautiful spirit. Then Lucifer asks if he needs to show that to Mammon, who apparently he was torturing during their entire conversation.