First, we should note that Nathan's judicial battle between his family and his former club Atlético Paranaense are seemingly over since his pre-contract signature back in May with Chelsea. Still, it was a complete mess.
Nathan's first appearance outside of club youth football was in 2013, when he joined Brazil's U17 side for the category's World Cup. Scoring 5 goals in the competition until Brazil's elimination in a penalty shootout against Mexico, the player was integrated into Atlético Paranaense's U23 squad which they used to play Paraná State Championships in March of 2014.
For the "alternative" squad playing against much weaker opponents, Nathan showed some of his good skills with his slick passing and good control in his dribbling runs. However, some Atlético fans complained that he lacked a knack for shooting on goal, as it seemed most times that he preferred passing the ball even if he was in a good position to take a shot.
Nathan was deemed good enough to join Atlético Paranaense's main squad for their Brasileirão (the Brazilian league) campaign in the middle of the year; but with his legal action against the club taking place almost right at the start of the league, he fell out of place in the squad, going from a rotation player to a mere back-up.
That is probably the main issue with Nathan: his legal battle was one of the major factors that affected his chances in the club. He featured in only 20 games - 8 of these as a starter - for the club across Paraná State Championship and the Brazilian league, accumulating 800+ minutes and scoring only one goal against Maringá, a lowly domestic club that features in the 4th division of Brazilian football.
Most of his highlights are almost two years old, coming from his certainly impressive showing in the U17 World Cup. Still, Nathan did not manage to impress as much once he got to play against professional footballers. He managed to impress people with his skills, but he was taken as lazy by some fans due to his lack of effort in marking from the attack in contrast with other Atlético Paranaense players with the same "background" like Douglas Coutinho and Marcelo Cirino.
He seems to be a player that picks up opportunities to make runs and is reserved to make such an effort only when he is confident that it will work. Otherwise, he will not do much unless he has the ball on his feet. He is also fast and he knows how to use his pace to his advantage, but his work rate was certainly amiss when he had his Atlético Paranaense spell.
It looks like he feels comfortable playing as a #10, being capable of driving down the flanks to cross the ball to the box with his right foot. He does not have a powerful shot and it does not look like he is a skilled finisher either.
I did not have the opportunity of taking a look at Nathan as close as I did with Kenedy, but speaking with some Atlético Paranaense fans most gave the impression that he's not a kid with a bad attitude. His only "red flag" would be his father and his agent and how they took over his career at such a young age, after he barely featured in professional football and jumped straight into a top level club like Chelsea.
His £4.5 million transfer fee will certainly not guarantee him a work permit and unlike Piazon, it does not seem that Nathan has any kind of family in the European Union to get a passport. He will probably join the loan brigade for some time but unlike Kenedy, I do not think he will feature in a Chelsea squad any time soon. Of course, he still have the benefit of doubt as he did not show his "true colours" like Kenedy did, but the glimpses he has shown do not indicate at the moment someone capable of starting for Chelsea or filling in for Oscar or whoever we have as a #10 in three to four years.