

That’s not very much information.
Are you talking about a commercial service? A free one (well, aside from mining your data)? Software that you run on local hardware?
You have the NSFW flag set on this post, but the post itself contains no NSFW content. Are you wanting something that can generate NSFW content?
There could be only one Rusty Shackleford.
They don’t have a replica of your brain, if that’s what you are asking.
Okay. In that case, I think that I’d probably use that, since there will definitely be information that I could show other people that only I know. Passwords, past private memories with people I know, that sort of thing. Maybe if one is optimistic, my doppleganger could guess or somehow obtain one or two, but if we do a number of these, I should be able to pass many more of these than my doppleganger.
Hmm. I’m not entirely clear here…are you saying the answer to both of the two questions is “no”? I mean, you didn’t explicitly say that the doppleganger has the same knowledge or the same possessions, but you also didn’t explicitly say that they didn’t.
Does my doppelganger have the same knowledge I have, or just the same outward physical characteristics?
Does my doppelganger possess the same physical objects I do, like an identical copy of a cell phone, say?
I’d get him something aimed at three-year-olds, and just get his dad a puzzle box:
https://en.wikipedia.org/wiki/Puzzle_box
https://kubiyagames.com/collections/puzzle-boxes