Now the first think that comes to mind in this matchup is that Lucas has his Magnet to counter Pit's arrows, and Pit's reflectors are a counter to Lucas' Projectiles, mostly PK fire. There's more to this battle than that.
First off, Pit has poor Melee range, and with Lucas' Magnet, it helps Lucas in bringing Pit closer to him. Be cautious that some Pits can use Arrow Looping to mess with Lucas' mind, simply mindgames.
Now, Lucas has some range and strong attacks, which some come out slowly, many of the moves outrange Pit's melee moves. Know that Pit's longest ranged moves are the F-air, and F-tilt, both dont come out as quickly as many of his other moves. This "Range" that Lucas has will hurt Pit.
For the projectiles, PK fire can simply be reflected by any one of Pit's 2 reflectors. The PK fire can cancel Pit's Rapid A move, but wont hurt Pit. This move isn't completely useful against Pit, though it can help Lucas recover and perform spacing, and with Pit's poor melee range, it could hurt Pit if he isn't careful.
PK Freeze is rarely used, because a Pit can just shoot an arrow at Lucas while he's using PK Freeze. Pit can also Reflect these to avoid damage, though it wont hurt Lucas... Unless Lucas is in the PK freeze's blast radius (Like that'll happen in a match). PK Freeze is bad against Pit... Smart ones anyways.
PK Thunder is one of those moves that can hurt Pit's recovering badly. Because it can hit multiple times for a lot of damage, as well as you controlling it, it can hurt Pit should he use his Mirror Shield, by just moving the PKT2 behind Pit. It also affects Pit's recovery, which I'll discuss later on.
When a Pit is trying to recover, a well-spaced B-air will spike Pit in his tracks, even while gliding.
-Man, why does poor Pit always have problems with many B-airs? Wolf's, DK's, Dedede's, Peach's...
Or you could use the PKT2 to chase Pit down while recovering. But remember, a Pit could just shoot an arrow at you as he is recovering.
Pit hates PKT2 when he's using Up-B to recover. This basically would lead Pit into getting KOed.
Pit does have good Edgeguarding, but sometimes, Dsmash nearby will get Pit with its range. I've experienced this before and it really hurts.
Lucas's N-air is similar to Pit's N-air in which both can pressure opponents' shields.
Note: Lucas' Fsmash, like Ness', when swinging the stick, it's a reflector.
Lucas' recovery isn't as limited as many other chars with poor recovery options, like DK, but can still be punished badly.
When Lucas is using the PKT2 to recover, Pit has many options to stop it.
1: Shoot an arrow at the PKT2 to cancel (Destroy) it and KO Lucas.
2: Mirror Shield Lucas right after the PKT2 hits him to reverse and KO him.
3: Shoot an arrow at Lucas constantly to build up pressure to mess Lucas up and force him to use PKT2 again, usually ends up getting KOed, depending on where Lucas is.
4: Edgehog Lucas, though hard to do if Lucas is just going to pass the ledge and land on the platform.
5: Use Up-B Near Lucas to "WingPush" Lucas while Lucas is trying to use PKT2 to recover, which can screw the player up, and make PKT2 hit Lucas in the wrong spot, which might send him somewhere else rather than where the player wants, which can also leave him open for one of Pit's attacks, should the Lucas be sent upwards.
Keep in mind that Pit is exceptional at Edgeguarding and ledgecamping, as well as gimping recoveries, or Gimping, in general, so fighting a good Pit with great Lucas experience will be hard when trying to get back to the stage.
Note: Pit has a D-tilt spike. If you hold on the ledge for too long, a Pit can just walk over and spike you. Lucas is one of the chars that can get D-tilt spiked while hanging on the ledge. The D-tilt spike works when the opponent is right at Pit's feet when he uses it.
Lucas' Advantages
-Is small and hard for Pit to hit.
-Has more range than Pit
-PSI Magnet weakens Pit's arrow game
-Powerful Moves could KO Pit somewhat quickly
-PKT2 and B-air are seriously dangerous to Pit when he's trying to recover.
Pit's Advantages
-Pit is good at Shield Pressure
-Pit's arrows can interrupt Lucas when he's using one of his "Vunerable" moves, like PTK2, and Dsmash
-Pit has many options to stop Lucas from recovering, mostly his PKT2, and some of those options involve arrows, which can keep Pit safe from harm.
-Reflectors slightly weaken Lucas' Projectile game, SLIGHTLY because Pit's 2 Reflectors can only protect Pit from the front, and not the back, and Lucas' PKT2, being controllable, you get the idea.
-Pit's Edgeguarding and Ledgecamping are exceptional.
Note: Norfair is one of Pit's BEST CP stages, but Yoshi's Island isn't Pit friendly.
Correct me if I'm wrong Pit/Lucas Boards
I'd say 60-40 or 55-45 in Pit's Favor. What do you think?