Best use of Charsi Upgrades for Assassin?

How should I spend my charsi upgrades? I thought about claws, but they are often crap, and usually the flail rune words are better?

Not sure what else I can use it for?

I should also add this is a Trapsin.

Imbue diadems, be level 93 or higher for best results (gamble a diadem from gheeds).