Ah, Maxwell. The great Cornetto. The epitome of a mediocre, but serviceable player, a meme with shades of cult hero. Lyon's own Lord Vasquez in a way. Maxwell has some highlights, some talents, and a certain versatility, but he's as a whole pretty unidimensional. I'd sum him up as decent counter attacker : runs fast, good agg, sta, and can shoot well (at times).
I don't think he'll ever adapt to fullback (his defending is still in the 50s after a full season there) and you lose his goalscoring while relying on his passing, dribbling, tw and def more (bad idea). Still, he makes for a decent wingback (or forward) in gameplans where you soak a lot and try your chances on a few counters. I think that's his only potential value in top leagues.