Zeno Zoldyck

Zeno Zoldyck (ゼノ＝ゾルディック, Zeno Zorudikku) is Killua's grandfather and Silva's father.Zeno is a witty old man, his advancing age has not dampened his quick thinking and speed in battle. Despite his senior citizen status, he is a very formidable tactician and a skilled user of Nen. He remains calm and collected at all times and displays a unique sense of pragmatism. He takes satisfaction in being an efficient assassin and that seems to be his only conceit. Killing is just a job to him and emotion doesn't enter into it. He only risks his life if there is a reward to be gained. Zeno has high hopes on Killua, that is why he trusts the boy's ability.