I really enjoy this, so an easy +1.
Two main issues for me, both of which I mentioned last night, but didn't have time to fully process or suggest anew:
#1: I'm not sure the O5 Council would be okay with this without better justification.
And I don't think justification is hard; something you said on IRC makes it hang together for me: "I like to think that it doesn't even want to really leave. It just gets bored. The Foundation is so serious and stodgy and boring… They need to learn to have fun." Just a bit more of a hint towards that should work.
Plus, most of the examples are pretty short term, and this is a bit of a long-term plan…
See… all the O5 Council needs to do is indicate that they have some reason to believe this SCP will stick around long term in his new role, and that the cost/benefit analysis comes out ahead. Even if they're wrong, that's justification.
It could be as simple as the fact that they were able to contain the SCP in the first place. Either they can re-contain him if necessary (because they've done it before), or they think that him staying on as an SCP was in and of itself a big joke, and if he wants to move on from SCP status, well… jeez, what can you do? Since he's still contained, maybe should call it a night here.
#2: This falls into the general cliche of "if you crosslink, make sure you crosslink exclusively to Series 1 SCPs, even though you're writing in Series 2/3". Might you consider adding some Series 2/3 links if people propose them to you?
EDIT: I see you added at least one! Woo. (Had missed that on first re-read.) Question above still stands, I suppose.
…And finally, a mostly irrelevant quibble: "Caucasian" is outmoded; you probably want "of European descent" or just "white". But you can get away with it if you like; it's still occasionally used in real-life scientific articles, and I don't downvote for such nitpicks.
(An irrelevant side note: This SCP is obviously Euclid if not Keter, but I'm guessing the "Safe" classification is a nod to the O5s' confidence and/or attempts to trick the trickster — so it doesn't bug me. I assume it's intentional, in fact, and the reader is meant to go through this thought process)
Whether you make changes or not, though, this SCP is highly entertaining, cleverly written, and entertainingly breaks a lot of writing taboos we've constructed for ourselves. On top of that, it's a seriously remarkable rewrite, of something I wasn't sure could be pulled off. And yet you did it. Awesome.