Krall is a barbaric warrior in the Teen Titans series.
He is a greedy and ambitious warrior who wishes to rule his tribe and have Sarism at his hand. He freed a witch and made her do his bidding. Krall wanted the witch to make him a champion. In responce, she summoned an army of monsters which were beyond Krall's strength. Cyborg was sent into Krall's time when Krall asked the witch to give him super-strength. Cyborg defeated the monsters and won Sarism's heart which made him jealous.
Krall took Cyborg to the witch's hideout where she created a portal for Cyborg to go back home. Cyborg refused and learned Krall's true goals. He attacked Cyborg but proved little match for his strength. Krall called the witch to grant him super-strength. The witch had several monsters merge with Krall turning him into a monster. Krall then defeated Cyborg by knocking him off a cliff into the river.
When the battle is on, Krall became the leader of the monsters. While Krall was fighting Sarism, Cyborg attempted to save her by using his cannon while being pushed away by the monsters but he was interrupted when Raven pulled Cyborg back to his own time. Raven then showed Cyborg a book that is was revealed that Sarism defeated Krall and his army and won the battle, much to Cyborg's relief.