Overboost(OB) cores are a basic for bladers because you'll often need OB to quickly close into range to blade, or flee when the heat is on. It's also useful for flanking the enemy.
FLEET and NI/MARE are perhaps the two best booster choices for a blader because of their output. However, the slower OX/002 boosters can also be effective if you use OB frequently.
There are mainly two types of "bladers" that are common in the AC community.
Pure blader - This is a blader with a blade as it's only weapon. These are hard to use and not likely to win against any competant person who are using ranged weapons but are fun to use nonetheless. They're probably most effective if they are Op-I.
Normal Bladers - These are the types that I like to use and are most effective. They use the blade as part of a combo of weapons be they shotguns, handguns, bazookas, machineguns, rockets, whichever.
Now for body types:
Lightweights - Lightweights make excellent frames to make a blader with. They're quick, and agile enough to get where they want to go, dodge when they need to, and bring the blade into play.
Midweights - Lighter midweights also make good blader frames. The MX/066 legs are great for these types because they're light, and are super manueverable. They also offer good AP, and you can pack on even more armor to survive close-range combat. The heavier midweights can also be effective since they can pack on so much armor.
Hovers - I've been semi successful using a PETAL hover AC on a blader. If you can get past the weird nature of hovers then they make good blader frames.
Quads - Perhaps the deadliest types of bladers, they employ the powerful PoD(Poke of Doom). Because they stab instead of slash, they aren't as easy to connect with, but if they do manage to hit then they can take off twice as much AP as a normal horizontal or verticle slash can.
Other parts: Arms that stand out as having outstanding blade performance are the REX, REE, and in my opinion, the SOL and MHL arms.
REX - Lightweight arms. They have very low defense, but a great energy supply, reaction speed(500), and low drain.
REE - Midweight arms with mucho energy defense. They also have the quickest reaction time(400) of all arms, as well as the greatest energy supply at 130. These are THE blading arms, yet they're not easy to equip because of the weight and drain.
SOL - These are the probably the best midweight arms in the game because of their weight to efficiency ratio. Regardless, they also are great for blading. With an energy supply of 110 and a smooth reaction time of 700 they work great on bladers.
MHL - I think these are good because of their good shell defense(which will help protect your AC from shotgun, machinegun, howitzer and bazooka shells that the enemy can threaten you with as a blader) They also have the same speedy reaction time as the REX arms.
Note: The MARTE arms are a preference thing. They have super slow reaction time and below average energy supply, but the slower swing gives you a longer and better tracking blade swing. I personally prefer a fast reaction but some like the MARTE arms for their supreme tracking ability.
Optional parts:
The LAP optional part adds some attack power to blades, but I rarely use it due to it's large slot requirement. Regardless if you see fit then by all means try it. It can give you that small bit fo extra power.
STAB is the optional part which increases the stability of your AC. Since you'll often be in close range this part is essential. It can totally nullify the stun caused by rifle shells, and help to weaken the otherwise crippling stun caused by handguns. It can also help to make it easier to avoid hard landings.
There ae three types of slashes that can be done with left arm blades.
Horizontal slash - An efficient powerful slash which swings directly to one side. Many prefer this type of slash over the vertical type, and it also seems to perform better when executing ground slashes. One must equip midweight parts(such as core or arms) to do this slash.
Verticle slash - This is a slanted downward slash that can be more effective than the horizontal slash when airborne due to it's increased ability to hit opponents who are slightly above or below you.(Note: Reverse Joint legged designs always have the vertical slash regardless of arm or core choice).
Stab(PoD) - The infamous Poke of Doom can only be performed by ACs which have either quadreped or tank legs. Since it's strike points are closer together than the other two types of slashes, it often generates damage in the upper three thousands even into the four thousands on full connect. Thus doubling the damage done. Regardless, the PoD is harder to perform consistently than the other two types of slashes so it takes some time to get used to.
Weapons: On normal bladers there are certain weapons which are ideal for support of the blade. Handguns can stun lighter and less stable enemies to give you an opening for a swipe or two. Shotguns are good to put pressure on the enemy while you try and close in, as are machineguns. Bazookas are good for some hard hitting close range offense and offer decent stun. Rockets are also great for comboing if you can work with manual aiming.
Extensions: Turnboosters are good for Overboost hooking the enemy(a simple move to flank the opponent). Backboosters are good on bladers for quick escapes, dodging and such.
Note: The blade tracking can also be used to dodge at times. It can send you over your enemy's head very quickly or off into a weird direction, hence making it hard for the opponent to keep you in their lock box. When paired with the turnboosters this manuever can be quite effective.
Head tracking: Many believe that blade tracking is affected by the head you choose. In AC3 many people think that the MX/003(aka the buckethead) Has the greatest blade tracking ability. It is true that it tracks well in the air, but I've also had success with the RE/008, SKYEYE, RACHIS, RE/005, and VEN, so I'm not too sure how different the performance of each is.
Hazards: There are certain things which can make the life of a blader a living hell. If there's one thing a blader should know in AC3, it's that the amount of mobility required for a blader to be successful depends on the size of the opponent's lockbox. The bigger their lockbox is, the more mobile you'll have to be to get around it. The more turning speed the better. Low defense lightweight bladers often cannot afford to blade head-on on the enemy since they'll often fall before the job is done.
First and foremost there's the Howitzer(especially the HZL50). It's the epitome of the anti-blader weapon. It'll stun you out of your attack, hurt you badly while doing it, and leave you open while the enemy continues going at you with their other weapons. Weapons like this make head-on blading very difficult and almost suicidal.
Second there's shotguns and slug guns. They are dangerous because they are most effective at close range, the ranges you NEED to get into to use the blade, therefore they can hurt you pretty bad if you stay close too long and punish you while you're on the way there. They also tend to have large lockboxes.
Machineguns are weapons that can really hurt a blader mainly because of their super large lockboxes which make it really hard to get around. Their constant barrages also make it near impossible to get into blading position without taking at least some damage.
Handguns. If you're a lightweight or anything else with low stability, then handguns can totally screw your blading attempts with their stun. Not to mention they can quickly send you into overheat if you just came out of overboost.
Bazookas can hurt pretty bad in close range as well as stop your blade attack. Rockets are the same. The Spread bazooka is especially deadly to bladers because of the manner which it fires.
I hope this helps anyone who wants to try blading.