Keris are very different then karambits. The karambit is not at all a piercing weapon, and was tipped with poison so that even a small cut would be lethal. Keris, on the other hand, were traditionally long weapons made for piercing, but were also practical for slashing. Traditional keris were originally fairly straight, but over time they developed into the waved blades that we now know as keris. A waved keris or kris was meant to scare the hell out of an opponent, as any slash could be lethal because the waves act like large serrates. Any thrust that hit a person would likely be lethal, and they were meant to be twisted up entering the body, causing a wound that wouldn't heal, and would bleed like hell.