Who could they be talking about?

From Explorers of Death V2:

https://www.deviantart.com/star-byte/art/PMD-Explorers-Of-Death-V2-198509408

"The screen slowly faded to black. I waited for something to happen, but nothing did. A text box suddenly appeared with no icon next to it. "???: Greetings, partner." Confused, I pressed the A button, "???: H-Hey... Y-you seem to be in a g-good mood..." "???: Quite. And you know very well why." "???: ..!! I do?!" I assumed that this was a conversation between two people, although I had no idea what they were talking about at all."