Help modeling a wing/fuselage junction (a karman)

Hi Onshape users !

I'm trying to design a RC plane. I imported a Fuselage surface, I designed a wing using the airfoil script from Darren Lynch, and now I'd like to blend them together like the real plane, with something that looks like a variable fillet, but extends from the trailing edge (see attached picture)

For now, in my document (Tab : "Fuse-skin"), a variable fillet is the best result I could achieve, but it's not quite what I wish... Could someone help me ?