Well, one thing you could do with the Shadowblade is turn it into something like a Daggerspell Mage.
Twin blades, one of body and one of mind, exist within us all. A true warrior is master of both.
Description: Daggerspell mages are wild cards, their magic comes in fits-and-starts, and few truly understand the strange bond they form with their blades. Like sorcerers, daggerspell mages seem to be born with this talent, but it is one that requires intense training a practice.
Role: With a knife flurry, the daggerspell mage explodes into battle laying low even the most experienced combatants. They appear seemingly out of nowhere, striking where it is least expected and dispersing into shadow an instant later. In one breathe the daggerspell mage enhances his abilities and those of his allies, while berating his foes with an onslaught of deadly spells.
I'll put the link up where you can get the full description of the daggerspell mage. Even if this idea was taken I wouldnt expect it to be copied verbatum or the same name used even, but I think some of these could fit the shadowblade quite nicely, especially daggercasting and arcane throw.
Daggercast (Ex): A daggerspell mage seamlessly weaves together the use of both spell and dagger. He can cast spells with a somatic compounds and material components, even when holding a dagger in each hand.
In addition, a daggerspell mage can channel a touch spell into his dagger, storing it until a successful melee attack is made, at which point the spell is discharged against the creature or object struck in addition to the normal damage that would be dealt by the dagger. A dagger may hold only one charge, but a daggerspell may carry any number of daggers possessing a charge on his person. The charge held in a dagger discharges harmlessly if weapon leaves the daggerspell mage's person.
Alternatively, the daggerspell mage may use a dagger to deliver a touch attack as part of the casting of a spell. In this case, the attack is made against the target's touch AC with all the bonuses applied to the attack roll associated with using a dagger (like Weapon Focus). If the attack roll is successful, the dagger deals no damage but the spell is discharged against the creature or object struck.
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and
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Arcane Throw (Ex): Starting at 14th level, a daggerspell mage can imbue arcane spell power into his thrown daggers. The daggerspell mage can deliver touch or area burst spells with a thrown dagger. If the dagger hits, the spell is discharged against the creature or object struck. In the case of an area burst spell, the creature or object struck acts as the point of origin for the burst. After the dagger is thrown, it returns to the mage just before his next turn (as if it had the returning special ability).
Additionally, charges held within the daggerspell mage's daggers do not discharge when not on his person. If the charge is not used within the day, it is wasted.
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Pretty cool, eh? Charging up a bunch of daggers, using them to stab foes to death with spells, throwing them, seems like a lot of fun. We dont have a class that has a reason to swap weapons often. So not only would this be a stealthy rogueish magic caster, they'd also be a kind of knife juggler, so to speak.
Also this one would be nice as well, getting the stealth trees bonus for certain spells could be very fun:
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Surprise Spells: A daggerspell mage of 16th level or higher may add his sneak attack damage to any spell that deals damage, if the targets are flat-footed. This additional damage only applies to spells that deal hit point damage, and the additional damage is of the same type as the spell. If the spell allows a saving throw to negate or halve the damage, it also negates or halves the sneak attack damage.
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the rest of it is at http://www.pathfinderdb.com/character-o ... spell-mage
obviously a lot of this wouldnt apply to ToME. Just a reference for some ideas for shadowblade enhancements.
Just saying. Imbuing spells into your daggers would be pretty awesome, or when you cast a spell at melee range it also does the damage of your main hand dagger.
this would also satisfy everyones desire to force the arcane blade to becomming a duel wield specialized character and leave room to improve its two handed abilities. Annointed Knight anyone?
