Jack (Tekken)

Jack is a character in the "Tekken" series. He has many successors since Jack bots are usually destroyed.
List of Jack-bots.
Jack.
Jack is the first robot in the Jack-bot series. It is unknown how it was destroyed. Jack was sent to get rid of Kazuya. Jack, unlike Jack-2, Gun Jack and Prototype Jack, did not appear in Tekken Tag Tournament making him the only Jack robot (before Jack-5) not to appear in more than one game.
Jack-2.
Jack-2 is the second robot in the Jack series. He is an upgrade of the original Jack robot and was sent out to enter The King of Iron Fist Tournament 2 to save his creator and friend, Jane from the evil Kazuya Mishima. In his ending, Jane and Jack-2 are playing on an island together. Suddenly, Jack-2 gets shot by a laser from a satellite up in space that Doctor Abel uses to destroy Jack-2. 
Gun Jack.
Gun Jack is the third Jack robot. There was no Jack-3 created.
Jack-5.
Jack-5 was not in any Tekken game as a playable character, but he can be seen in the Tekken 5 opening movie (these Jacks are sent to kill Heihachi Mishima).
Jack-X.
Jack-X has been appeared in Street Fighter X Tekken.
Jack-6.
Jack-6 has been appeared in Tekken 6.
Jack-7.
Jack-7 has been appeared in Tekken 7.