Sequence
From Sega Retro
I think the problem is actually {{{4}}}
it appears that Mediawiki only evaluates arguments once, and it only does that when it finds a reference to one in the code. So it's getting to {{{4}}} on the first loop, evaluating the argument, replacing the {{#var:region}} bit with "jp" and then doing nothing on the subsequent loops because in its mind, {{{4}}} has already been evaluated (so it just substitutes subsequent 4s with the one it's already done).
I don't know how you'd get around it - my only thought is to do something like this
{{sequence|region|,|jp,us,eu| * md_date_$1 }}
and then do a string replace on "$1" (Notepad++ uses $x for regex subtitutey bits). I tried doing a string replace on {{#var:{{{1|}}}}} but Mediawiki wasn't having it -Black Squirrel (talk) 14:58, 6 February 2018 (CST)