Since we're discussing the Match-Up with the Mii Fighters, I did an analysis on Kirby vs Swordfighter and Gunner. I figured that I could post it here as well.
Kirby vs Swordfighter
Any height Swordfighter seems to work fine against Kirby as long as it isn't taller than Average height. Taller Swordfighter doesn't seem to give much as far as advantages go in the MU, and can actually make fighting Kirby more difficult due to his small stature.
Average-height Mii Swordfighter seems to deal with Kirby's small size decently well. The reach of attacks is plenty good with this height to beat out Kirby's options.
Smallest Height gives better mobility which helps in the neutral game, pressuring, follow-ups, and playing more safe. Reach of attacks may be slightly shorter, but they still have plenty of advantage when spaced against Kirby's attacks.
Although the Smallest/Lightest Swordfighter's mobility is best, it is only when using Smallest/Lightest Swordfighter that attacks seem to be too inadequate to deal with Kirby's attacks. Light weight is an additional drawback that seems to make a notable difference when exchanging blows.
Usually "sword" characters can be difficult for Kirby because of their disjointed hitboxes giving them range advantage when using attacks in neutral or to force an opening. They can "out-poke" Kirby and force him into a defensive stance.
Mii Swordfighter, however, doesn't boast a very strong "poking" game compared to prominent sword-uses like Cloud, Marth/Lucina, and Corrin. He also doesn't boast great frame-data, meaning that if he's doing the wrong thing at the wrong time he leaves himself wide open for a punish. These are things that Kirby can capitalize on and make the MU much more manageable. Swordfighter does not get outright KO's with a Grab, nor does he have great shield-breaking options. This makes Shielding a reliable option for Kirby in the MU.
When choosing Swordfighter's Standard Special, it's important to know what it is that you want to do since each of the three have different uses.
Standard Special #1 "Gale Strike" has more start-up and endlag but it is unique with its multi-hits and its "wind" effects. Gale Strike tends to be more useful against characters that use projectiles that get knocked away with this attack and Kirby doesn't have that.
Standard Special #2 "Shuriken of Light" is a quicker attack than Gale Strike, but it doesn't stay out as long and is best used to disrupt the opponent or harrass them at longer ranges. This works quite well against Kirby since Kirby cannot crouch under the Shuriken.
Standard Special #3 "Blurring Blade" is a close-range, multi-hit attack that deals decent damage and can KO with the final hit fairly well when fully-charged. It is best used when the opponent's Shield is already damaged or to catch someone Sidestepping or Rolling at Swordfighter. It can also be used off-stage to gain a horizontal boost when fully-charged.
Mii Swordfighter's
Side Special #1 "Airborne Assault" (AA) works well as a horizontal recovery move, but seems to be lacking in general as an offensive attack. It can be used as sort of a surprise or something, but the risk vs reward doesn't seem to pan out, especially considering Kirby can duck under AA if he is under it's apex when it reaches him.
Side Special #2 "Slash Launcher" overall seems weak, offensively, but it can be used as a form of horizontal recovery to get back from a distance. I feel like AA is a better choice in this regard.
Side Special #3 "Chakram" is an excellent projectile that can be used at mid-range for a multi-hit attack with follow-up possibilities as well as long-range with a "Smash Charge" to make it a single-hitting attack with more distance. It is important to note that Kirby cannot crouch under Chakram, and even if he could the Chakram can be angled downward to hit him.
Each of Swordfighter's Up Specials can be used as a form of recovery to get him back to the stage.
Up Special #1 "Stone Scabbard" (SS) is a quick vertical option that can help get to the ledge faster than Kirby can launch an offense, but it lacks horizontal recovery and doesn't auto-snap to the ledge. It can be used to spike Kirby when Kirby is using Final Cutter - simply hit Kirby as he comes up toward the ledge with the Stone Scabbard's downward thrust.
Up Special #2 "Skyward Slash Dash" (SSD) is perhaps the most reliable of recovery moves. It's slower to start and slower when moving than the other two options, but it can be angled and has a multi-hit slashing barrage; both of which make it difficult for Kirby to intercept.
Up Special #3 "Hero Spin" is a decent enough recovery move, more limited than SSD but less limited than SS. The trade-off is that it is also a decent Out-of-Shield option.
Down Special #1 "Blade Counter" is the stereotypical counter move. It's a good one, and a decent enough choice in the MU if you are good at predicting your opponent.
Down Special #2 "Reversal Slash" would be almost pointless against Kirby except that Kirby cannot grab the ledge with Final Cutter, so if you can hit him with a Reversal Slash as he attempts to land on the ledge you can gimp his stock. It also has a corner-case use against Kirby's Gale Strike if he has Copied it from Swordfighter.
Down Special #3 "Power Thrust" seems to be a weak choice, in general, as it works similarly to Slash Launcher.
The MU seems to be mostly even, with advantages going for Kirby, if anyone. Kirby doesn't have too much problems dealing with Swordfighter's disjoints and pressure, and has stronger damage building options, better KO options, a better Grab game, and strong options when Swordfighter is off-stage at disadvantage. Swordfighter has some reliable moves, specifically Up Air when Kirby is above him (assuming you're watching out for Stone) and Down-Air when Kirby is off-stage. Swordfighter's reach may not be as good as the representatives from Fire Emblem, Final Fantasy, et al, but he still beats Kirby in spaced attacks.
Stage choice doesn't seem to make a huge impact in this MU. Kirby will probably want platforms. Swordfighter may want to go to Town & City.
Suggested Size and Special settings:
Average/Medium height/weight works perfectly fine, as does Small/Medium.
(1) Gale Strike / (2) Shuriken of Light / (3) Blurring Blade
(1) Airborne Assalut / (3) Chakram
(3) Skyward Slash Dash
(1) Blade Counter / (2)Reversal Slash
Kirby vs Gunner
Gunner's best choice in the MU is to use the smallest height for the best mobility options and to help hit Kirby when he's crouching. Any weight class can be usable since lighter weight adds to mobility and heavier adds to survivability and power. In general, it's probably a better choice to avoid the lighter weight in the match-up since a short height will give enough mobility to camp or pressure Kirby as needed.
Both
Standard Special #1 "Charge Blast" (CB) and
Standard Special #3 "Grenade Launch" (GL) have their uses against Kirby and are both good choices. The CB gives Gunner a strong option at long-range, and the full-charged shots can actually be useful for netting KO's on Kirby since he is light. GL pressures from longer distance and works well on Shields which Kirby often relies on in the MU due to his poor mobility and range options.
Standard Special #2 "Laser Blaze" (LB) is the least valuable of the options, and is somewhat worse in this MU than most other MUs because Kirby's crouch keeps him safe the same way it does against Fox/Falco's lasers. In other words, LB is even more useless in this MU than most other MUs.
Side Special #1 "Flame Pillar" (FP) can be used at mid-range against Kirby to shut down his approaches and can catch his pokes (usually D-tilt). When used while retreating (Dash away and then skid-cancel into FP) it can discourage Kirby from approaching since it will catch any Short-Hopped Aerial Attack he will throw out while approaching.
Side Special #3 "Gunner Missile" can also be useful, but as a long-range option or when Kirby is off-stage. Smash Missiles are strong and can damage Shields, but Kirby can usually duck under those as they are easy to see coming. Tilt Missiles help zone against Kirby and can home-in on him, making them valuable against a long-range crouching Kirby.
Side Special #2 "Stealth Burst" (SB) is not a commonly-used option, but could have it's use to hit a crouching Kirby or if Kirby is off-stage and recovering level to Gunner's aim with the SB. Most Gunners might go with Missiles, but FP has uses and SB might even be a contender though it is unconventional.
Gunner's recovery options with Up Special are not too different from each other. They all shoot Gunner upwards, so be wary of Kirby's attacks from above.
Up Special #1 "Lunar Launch" (LL) is commonly used by Gunners since it provides a solid recovery option, a decent projectile under to hit a Kirby who may be jumping back to the stage or starting up Final Cutter, and has low landing lag should Gunner have to land onto the stage or a platform.
Up Special #2 "Cannon Uppercut" (CU) is a strong option if you want to add KO power to your Gunner - something that may be useful if using shorter/lighter Mii Gunner. It's relatively poor vertical recovery can be off-set by the smaller Gunner's enhanced jump height and air mobility. Kirby is also fairly susceptible to being hit with the spike hitbox of the CU since he is slow in the air and has a predictable recovery with Final Cutter having 23 frames of start-up before it begins to rise upward (and it doesn't auto ledge-snap either). For these reasons #1 and #2 seem to be more advantageous to select than
Up Special #3 "Arm Rocket" (AR) since the AR doesn't add too much more height compared to Up-1 (LL) and has no hitbox either.
Down Special #1 "Echo Reflector" is not especially good in this MU, but it has it's uses. First, it can be used to stall while in the air and to turn Gunner around to face the other direction, should that be needed (such as for Gun Dashing during recovery). Second, it can be used against Final Cutter's shot or against Charge Blast (should Kirby have Copied it).
Down Special #2 "Bomb Drop" is very useful for pressuring from above and does decent damage to Shields. It couples well with other attacks that pressure Shields such as Chrage Shot or Missiles (Smash Missiles, specifically, though Kirby can crouch under those). Bomb Drop is a good alternative if you are not using Standard Special #3 (GL) and is also good coupled with GL for added explosive pressure forcing Kirby to go defensive, or to force him into the air where he is more vulnerable.
Down Special #3 "Absorbing Vortex" is not often useful in this MU, with it's main use being a defensive option against Kirby who has copied Charge Blast.
Overall, most of the MU boils down to Gunner falling back on his/her superior long-range options with Kirby wanting to move in close. Gunner has an easier time out-maneuvering Kirby, especially in the air, aided with Gun Dashing and smaller sized Mii makes this even more obvious.
Kirby, however, can still close the gap and make his way to close-quarters often enough to count and when he gets in close he can lay on a lot of damage and has decent enough mix-ups. Kirby's main form of approach would usually be with an Aerial Attack (such as N-air, F-air, or U-air - preferably a reverse-dropping Up Air) or with tactics to catch Gunner with a Grab (often with feints, crouching, and Shield). If you give him an opening, he's going to make the most of it.
Neither Gunner nor Kirby have great KO set-ups, especially not at low percents. This means that whomever is not taking damage is winning, in theory. Both characters will usually opt for safer options unless it nets them a KO, and the safer the KO the better.
Gunner, for example, will want to continue shooting things at Kirby until he/she can get a KO from one of the long-range options like full-charged Charge Blast, or a stray Grenade or Bomb at high percents (like at 130% to 160% depending on Rage). And Kirby will opt to build damage and gain positional advantage until he can get a safe KO with B-air around 100% (at the ledge) or Up Throw around 150% (no Rage, no Platform, Guest Weight - a few percent less for lighter Mii, like 147%)
Both Gunner and Kirby can opt for more risky moves at lower damage to get earlier KOs. Gunner can use Up Smash, Down Smash, F-smash, or Canon Arm. Kirby can try to land Forward Smash or Up Smash. He also has Hammer, but that should be shut down by zoning options from Gunner easily. Gunner will probably be better off playing a solid zoning game until he nets a KO with Up Air or D-tilt. Likewise Kirby's better off getting his KO's with B-air (Out-of-Shield, RAR, or retreating) or when he has Gunner off-stage.
In general, Gunner will want larger stages to keep Kirby at bay. Kirby will want smaller stages. Platforms can help both characters in various ways, so the number and formation of platforms doesn't matter too much. Kirby will probably want to avoid Duck Hunt and Gunner will want to avoid Town & City.
This match-up is fairly even. It falls upon the players to play to the strengths of their characters and make the right choices at pivotal times. If one player fails to keep up with the opponent's strategy, it can seem like an uphill battle but there is not a significant advantage to either side.
Suggested Size and Special settings:
A smaller gunner is advisable due to Kirby's height and crouch, though Average size works fine. Weight is user-preference, but lightest weight coupled with smallest height seems to be possibly a little too light.
Lots of Special combinations work perfectly fine. It is suggested you don't use Laser Blaze.
(1) Charge Blast / (3) Grenade Launch
(1) Flame Pillar / (3) Gunner Missile
(1) Lunar Launch / (2) Arm Cannon
(3) Bomb Drop
Bayonetta: 143 - 154
