I liked your 'delightful' one :) Took me a while to figure it out, but it's a bit sneaky in that's it almost all trickery magic. I got the obfuscated bit down too:

($^X ) = ($^X ) =~ m/^ |perl|;/g;
@XX = '3"; ' ^ (per);
($^X ) =~ s/[perl]{4}/@XX/;
print("$^X\n");
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The CGI bit comes from matching the '3"; ' ^ (per);. I especially liked the first $g or die, took me a while to realise the whole thing was a match starting with the $ on line 4.