A Pilum would be cool Although I have only read about them being used by the Romans which leads me to think they somehow lost there effectiveness as the development of steel came. Could be 1 ammo but with a x3-4 bonus to shields to simulate how useless they made shields when stuck in.
Caltrops but make them 2-3 slots so the battle severs don't become a mine field.
Probably not possible but a sort of sword breaker or parring dagger, and some how made it so you had to use directional blocks. So one one handed swords could retain there speed without spending a dual being stunned by weapons 2-3 times there weight.
And a Jian although it would probable end up having the same stats as the Espada Eslavon