The Tzzin are a race of reptilian humanoids that have some resemblance to electric eels. They are capable of generating and discharging electric charges through their hands.
With their Stone Age equivalent, it was enough to simply ambush a creature, jump on it, and discharge as close to the heart as they could. But now things are moving forward and some tribes have begun experimenting with metals and other resources to create better ways to store and discharge their electric charges.
If necessary, consider they have evolved some form to prevent themselves from beign eletrocuted.
Their society would now be the equivalent of the Greek City-State stage, but with a much better understanding of how electricity works.
The main question is: What kind of weapons (melee and ranged) they could have that makes use of their natural abilities?