Incredibly far reaching attacks, powerful kill moves and being relatively fast for such a big guy makes Donkey Kong quite the formidable opponent. It doesn't help that he is also the second heaviest character in the game but, how does he fare against Paletuna's loyal servent?
DK easily outranges Pit and due to the strength of his attacks and his heavy weight, you're going to be seeing DK live to some obscene percentages while you will find yourself simply being KOed around 100% if you try to take him head on. However, Pit is hardly at a disadvantge in this matchup. On the contrary we could say Pit actually has the overall advantage! Pits Arrows play a key role in this fight, limiting a number of DKs options and allowing Pit to get kills easier than one might initially expect. DKs are infamous for their effective Bair approach which can be quite problematic for most characters, however, this isn't the case with this angel as Pit's Arrows disable this approach and force DK players to find an alternative means of approaching.
Pit's Arrows also eat up DK's midair jump relatively easily, which leads me on to another one of Pits advantages in this matchup, the Mirror Shield. As we know the Mirror shield is capable of reversing the direction of most melee attacks and DK's Up B is no exception. Off the edge DK is already vunerable due to his limited options for recovery and Pits exceptional ability to gimp most opponents but the Mirror Shield's attack reversing capabilities means that a DK forced to use his Up B is pretty much a dead DK.
With these satiable amount of advantages one might think that this match would be entirely in Pit's favour, but of course things are never that easy. DK isn't exactly going to walk off the edge for you to kill him. The hardest part of the matchup is in fact actually forcing DK off the edge to try to edgeguard him. DK is heavy, and difficult for Pit to force off the edge and its unavoidable, you had to get up in this big apes face at some point. This is where DK excels and where Pit needs to be most careful to avoid DK racking up too much damage and scoring an easy KO with his multitude of killing moves. Watch out for DK's Dtilt, which has long reach and is capable of tripping you, which can set you up for another combo, DKs' Nair is also extremely good and kills at low percentages and DK's Up B has super armor frames so be extremely wary of these three moves. DK is not without his own problems at close range though. At the beginning of a stock Pit can chaingrab DK to about 40% and then follow up with a down grab to Uair resulting in a decent amount of damage. Pits nairs are also extremely effective at wearing down DK's mediocre shield and can rack up major damage, the same can be said for Pits Uair and an airbourne DK.
At the end of it all this is one of Pit's easiest matchups and a totally uphill battle for an opposing DK. Take advantage of DK's big frame with your multi-hitting moves, arrows and his gimpable recovery and watch out for DK's powerful kill moves and you should come out on top.