Thanks a lotIn the first Spider-Man comics after the debacle that was Maximum Clonage, Ben revealed that he'd had a past encounter with D'Spayre, a demonic foe of Doctor Strange who --- like his name would suggest --- specialized in driving people to despair so he could feed off it and had come after Peter specifically in that issue. However, there was sadly no flashback story that elaborated on said encounter, just Ben revealing that he knew who D'Spayre was and helping Peter beat him. Oh, and for what it's worth, my personal canon is that D'Spayre was f***ing with Ben the whole time Miles Warren was torturously murdering and resurrecting him over and over and that was why Ben came out so f***ed-up and twisted that he ended up going as bad as he did in The Clone Conspiracy, D'Spayre's revenge for Ben beating him before. Plus, he did appear as the main villain in the second season of the Cloak & Dagger TV series, albeit as a human empowered by the same accident that gave Ty Johnson and Tandy Bowen their powers who later ascended to a form of godhood.
P.S. I like Land's rendition of Ben's Spider-Man Beyond costume.