With apologies to Nathan Mackinnon, Mitch Marner of the Toronto Maple Leafs is the 3rd best forward, and 4th best player overall, in the world right now.
The Toronto Maple Leafs second-best player is the fourth best player in the NHL, after Auston Matthews, Connor McDavid (they are co-best players, as Matthews goals and defense are, at least, the equal of McDavid’s points) and Cale Makar.
Markar is probably also elite defensively, and he has over a point per game in his 178 game career, and a Stanley Cup, and a Norris Trophy. He is the best defenseman in the NHL since Erik Karlsson was in his prime, and likely will surpass even Karlson to be the second best since Nick Lidstrom.