Piccolo

Piccolo is really one the best of the Z fighters at making and using chi techniques. He has been able to use it to defeat some of the most powerful enemies the Z fighters encounter even though he is no longer considered one of the stronger characters. He was the only one who could kill Raditz, even though his power level was significantly below Raditz's. He was even able to defeat Dr. Gero even though Dr. Gero had added Piccolo's powers to his own. Piccolo's father, Demon Piccolo, was Kami's evil side given physical form and ejected from Kami's body, so he was purely evil. Though Piccolo is the son of this "demon", he is not purely evil. In fact, his race is generally peaceful. His evil actions are caused partly by his desire to avenge his father, who was killed by Goku, but more by the horrible evils he witnessed on earth.