Nemesis is the 13th and final episode of Ultraman: Towards the Future. It is also called Eternal Hero -Two Legendary Monsters Appear- (永遠なる勇者 -伝説2大怪獣登場- Towa-naru Yūsha -Densetsu Ni-dai Kaijū Tōjō-) in Japan.
The episode starts Colonel Grant and the other UMA members wondering where Jack Shindo is, as they cannot find him. Grant says that Jack could help them uncover what a strange metal disk can do. It then switches to Great talking with a semi-conscious Jack, with the Ultra telling the human that his next transformation may be his last. Jack wants to go try to stop the kaiju, with Great agreeing. Back to UMA, Grant and Jack are attempting to translate the writing on the disk. Jack finds the name of the two attacking kaiju, Kodalar and Kilazee. Col. Grant then goes to a museum to decode the disk, before being attacked and knocked out by a man who steals the disk.
It switches to a man speaking to a group a people about the evils of missiles and nuclear weapons. Back at UMA HQ, a military commander, General Brewer, prepares to launch missiles at "this bird". Again switching, this time to Jack stating that even Ultraman is able to be beaten. Changing characters once again, this time to Lloyd and Jean sneaking through several large metal containers. A man, Ike, throws two filled burlap bags at them, before telling them that he believes the end of the world man. He then runs off. Right after this, Kodalar attacks the area.
Back at UMA HQ, Brewer orders missiles fired at "the fish," with no apparent effect. The man seen earlier then attempts to offer the disk to the kaiju, while lloyd and Jean watch on. In space, Kilazee begins to burn the atmosphere with his fiery breath. He then goes on the attack, destroying building with his lasers. Lloyd and Jean prepare to crash their jet into the kaiju, while the UMA tries to dissuade them. Kilazee dodges them, before escaping. The sky is covered by a black could, and Charles' satellite is having faults. Back at the docks, Kilazee begins to attack while the UMA members discuss Brewer. In a humorous moment, they state that Brewer will have to wait his turn for attacking.
The UMA takes the disk to a hill, overlooking the kaiju. Setting the disk into large cannons, they prepare to shoot Kodalar, but before they can Kilazee attacks from above. The laser cannons have no effect on the kaiju, while Jack transforms into Ultraman Great. The two kaiju tag-team him, with Kilazee using his sharp head like a spear. Kodalar opens fire at the UMA, his lasers being reflectd back anf forth from the dish to his hands, before destroying both the disk and kaiju. Kilazee takes to the air and begins to burn Great, whose Color Timer is ringing. The Ultra then used the Great Double Slicer to kill Kilazee. Great then took the corpse and flew it into space, while Jack returned to the UMA. The humans watch the Ultra fly away, while Jack utters the last lines of the series, "We've been given another chance."
- Colonel Arthur Grant: Ralph Cotterill
- Jean Echo: Gia Carides
- Lloyd Wilder: Rick Adams
- Charles Morgan: Lloyd Morris
- Kim Shaomin: Grace Parr
- Jack Shindo: Dore Kraus