Ajax needed the nightmare fruits to become stronger using the new system function 'Nightmare World'.
Therefore, Ajax was willing to pay the market price for the nightmare fruits.
"Young master, I have five nightmare fruits with me back in my treasury. I can give them to you for a smaller world core. What do you say?"
Nightmare Fiend thought about it for a moment and proposed a deal.
"Deal."
A smaller world core in exchange for five nightmare fruits. It was a nice deal for Ajax. Hence, there was no need to reject it.
"However, let me inform you something."
Unlike the elemental human emperors, Nightmare Fiend treated Ajax with honesty and wanted to say some truth about the Nightmare fruit.
"Only the Nightmare fiends can consume it three times and as for the other races, they would be killed if they consume more than one. So, I suggest the young master consume more than one."
"I already know that. Thanks for the reminder."