But that would make the card even more powerful no?
Could be made with modes:
Discard lowest cost
Discard highest cost
and raise the card cost to 2-3 gems.
Otherwise if you'd choose to buff Samurai, I could propose one of 3 things:
a. give it Far Sight keyword
b. give it Swift keyword. A Samurai is a master swordsman, so he must be swift right? :)
c. force the opponent to not draw rare.