Sixten are the dude that did that Shizuha/Lunasa story?
If you're talking about
Autumn Children, which is posted in a thread in the Atelier section of these forums, yes, I am the same illustrator.
As for American Football, I'm a Packers fan living in Seattle (see: Fail Mary). I normally don't draw sports-related stuff (I think the last time was a genderswapped Kevin Garnett maybe 4 years ago), but the whole Utsuho Ravens thing was too interesting for me to pass up.