Take a look at Incarnate. (Make very sure you read the handbook though, as the book itself is horribly written.)
Before I go into incarnate though, there is a literal way, with a shaper, of making power armor. It's certainly cute, and if it fits your desired power level, use it and don't look back.
On the other hand, there's Incarnate:
- Shapes soul-stuff into blue-glowing armor and weapons.
- The summoned armor and weapons can be remarkably awesome
- Excellent, with the right build, at being a tank.
- Has the capability of shaping flight soul-melds.
- It's all about enhancing capabilities rather than casting spells.
- Incarnate Avatar is a literal body-outside-body power armor.
While there are some excellent multiclassing capabilities, it sounds like your player is relatively new to the game, and Incarnum is hard enough to handle as it is.
On the other hand, as an intellectual exercise, let's see how literal we can get with these requirements. The wiki says:
Shardbearer is a term used to refer to a person who holds a Shardblade or Shardplate. A full Shardbearer is a person wielding both Shardblade and Shardplate.
... A Shardblade is a powerful weapon capable of slicing rock and severing souls. ... Shardblades cut easily through most inanimate matter, so long as the blade is kept in motion. They do not cut living flesh; instead the metal fuzzes as it passes through, killing without leaving a mark or spilling blood. It was said that Shardblades sever the soul itself, the only indication of death being that the victim's eyes burned. ... Honorblades are believed to grant some power over the paired Surges (i.e.: Jezrien's Blade grants Adhesion and Gravity; Nale's Blade grants Gravity and Division, etc.).
The armor simply is super-strong buffing armor.
The first option to look for is if we can emulate the soul-slicing element of the blade. While our fall-back plan is to just presume that that's flavour, ability damage or level drain may do the trick. Our best bet here is the game-breaking (we're talking instant-kill lightsabres here after all) shivering touch. The way we're going to do this is divine casting + 3 levels of ordained champion.
Worships Hextor or Heironeous.
The cleric components of this build are a very good thing. Not only does it give us access to shivering touch, but it gives us access to divine power, or "I don't care about my 'real' BAB, thanks." It also completely solves the "caster-like" abilities part of the requirements by... being a caster.
Beyond that, we'll be spending the bulk of our time in the Sapphire Hierarch because of this:
That said, you can do wonders with your spells if you just buff yourself even a little bit. A simple Divine Power+Righteous Might+Holy Sword on your Incarnate Weapon with the Spellward Shirt and Incarnate Avatar active= Demigod-level Attack rolls. It's actually possible for you to sink half of your BAB into Power Attack and still hit with a 10. The sheer number of buffs you have access to is absurd, even by Cleric standards.
- Azurin Cleric/1
- Domains: Law, War. Worship Heironeous for the Longsword favoured weapon because a shardflail sounds funny. We're not going to go for early entry shenanigans, because we're preparing for divine metamagic.
- Feats: Extend Spell, Shape Soulmeld (Airstep Sandals). Weapon Focus (Longsword) (free)
- These first feats are completely worthless until later. If this build needs to be viable from Level 1, you may want to juggle domains and feats slightly. Still, airstep sandals are neat, and flight is always awesome, especially this early.
- Spells. Looking here, we have Command and Lesser Vigor.
- Equipment. Masterwork Longsword, bag of adventuring supplies, the best heavy armour you can afford.
- Stats. You want a high Str and a good Wis and Con. You'll want a very good charisma depending on how your DM rules nightstick stacking.
- Soulbind: Incarnate Weapon (because that's iconic for the build and... pretty good, actually)
- Incarnate Avatar. +1 insight bonus to melee attacks is great especially on top of a +1 longsword of pure law. Having all of these bonuses is a good thing because of the severe MAD you're facing. (a decent strength, a decent wisdom, and a very good constitution.). Still, this is a very neat level.
- Cleric 2.
- Feat: Persist Spell. (It's kind of pointless now, so you may want to go for law devotion instead and retrain later)
- Cleric 3.
- You get access to second level spells here. Divine insight is your friend, as can be Bewildering Substitution.
- Sapphire Hierarch/1
- Ordained Champion/1
- Feat: Divine Metamagic. This is the point where the power level of this character starts taking off. And he'll be placing bulk orders for nightsticks. Supply to whatever level the character needs a buff due to playstyles.
- Free domain: Essentia. (Gained instead of the war domain). The other domains are nice, but if you're planning to go into high levels, there are some nice domain-only spells here.
- Ordained Champion/2
- Ordained Champion/3
This is a big level. We've mostly been ignoring our meldshaping (despite walking around as a large golden god) to try to power to here as soon as possible. We've lost two caster levels, so this level, we get both channel spell and third level spells (shivering touch.) Ergo, now, you can stab someone and cause 3d6 points of dexterity damage, which is the best "I'm damaging your soul" map the game has.
9..17 Continue with sapphire hierarch. Feats should be chosen according to the various handbooks.
All told, the early levels are extremely fiddly to work around stats and feat wise, but the combination of ordained champion + shivering touch + incarnum weapon + incarnate avatar fits the requirements to a T.