Tidus

Tidus is a minor character in the Kingdom Hearts series, and one of the characters originally from the Final Fantasy franchise. He is one of the residents living in Destiny Islands and is part of a trio including Selphie and Wakka.

He is thirteen years old during the events of Kingdom Hearts and Kingdom Hearts: Chain of Memories and fourteen during Kingdom Hearts II.

Kingdom Hearts
Tidus is a friend of Sora, Riku, and Kairi, and is a resident of the Destiny Islands, spending most of his time with Wakka and Selphie.

In Sora's 'Dive to the Heart', Tidus appears in the Destiny Islands area along with Wakka and Selphie. His question, like the other two, determines Sora's leveling pace for the rest of the game, asking: "What are you so afraid of?". Sora can answer the question in three different ways. Either A) getting old, B) being different, or C) being indecisive.

Later, on Destiny Islands, if Sora talks to him, Tidus will offer to duel Sora. If Sora declines the fight Tidus will have multiple possible remarks; the most notable being that he and Wakka are working on some type of underwater ball game, which is a reference to Blitzball from Final Fantasy X.

If Sora loses a practice battle with Tidus on the second day in the Destiny Islands, Tidus performs his victory pose from Final Fantasy X, namely, tossing his sword upward then catching it before swinging it to his side.

It is unknown where Tidus disappeared to after Destiny Islands was destroyed.

He is last seen playing with Wakka and Selphie after the island was restored in the end credits.

Kingdom Hearts: Chain of Memories
Tidus appears with Wakka and Selphie in both Sora and Riku's stories as part of the memory-based Destiny Islands in Castle Oblivion. Some time after Sora goes to sleep, the real Tidus is seen playing with Wakka and Selphie on a beach while Kairi is facing the Small Island.

Kingdom Hearts II
He and Wakka do not appear in Kingdom Hearts II, but Selphie mentions that he and Wakka are "All wrapped up in their ball game," which furthers the Blitzball reference from the first game.

Unlike the original Kingdom Hearts, which pronounced his name with a hard E sound (Tee-dus), when Selphie mentions him in Kingdom Hearts II, she says his name with a hard I sound instead (Tie-dus). It should be noted, however, that the katakana of his name, though romanized as Tidus even in the Japanese versions of Tidus's appearances, is read as (Tii-da) (ティーダ Tīda), and is derived from the Okinawan word for "sun". As the Japanese "ィ" is pronounced like the English "E", it would suggest that the Kingdom Hearts pronunciation (Tee-dus) would be closer to the Japanese equivalent. Additionally, Dissidia Final Fantasy and interviews with Tidus's voice actor confirm it as "Tee-dus", indicating that this may have been an error.

Kingdom Hearts coded
Tidus makes a third appearance, this time as a data version of himself, alongside Wakka and Selphie. He appears on the data version of Destiny Islands, collected from memory of before it was destroyed by the Heartless. He was searching for the reason behind the blocks all over the island. He saw the Black Coated man right near the waterfall, but doesn't tell Sora of the man's whereabouts until Sora defeats Tidus.

Abilities
Like in Final Fantasy X, Tidus fights with swift movements and much dodging. His trademark Brotherhood sword, given to him by Wakka in the original game, however, is replaced with a bokken.

On Destiny Islands, he practices fighting skills with Sora as a way for the player to improve his level. During this battle, he fights by stringing together combination attacks. If Sora manages to block one of his sword attacks, 2 Tech Points are earned per block. After defeating Tidus, Selphie and Wakka as individuals, Sora is able to fight against them all at the same time.

Role in the series
Though not as crucial in fighting as his FFX counterpart, Tidus still has a place in Sora, Kairi, and Riku's lives as the three go to watch his blitzball games with Wakka as he managed to bring his underwater ball game idea to it earning him fame. He attends Sora and Kairi's elope in Radiant Garden even though he thought it was more likely she'd marry Rika, because he and his other two friends felt they were hardly there for them.