With katanas you have a few: Malakar, the Dakkon Zerth blade, couple +2's and +1's. As for ninja-to's there is only a +1 unless you are playing a Monk then you could use a +3 that is only available to them. Umm, scimitar's were addressed in another post not to far from this one; two +2 scimitars and one +3. I agree with you about there being way too many longsowrds and not enough other types of blade weapons.
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Can an elf get a break anywhere these days?