Cloud Strife was raised as an outsider, either ignored or accused, and inevitably a trouble maker when he only wanted attention. Thus he decided to join SOLDIER when he came of age to prove that he was worth more than dirt. Unfortunately, he was not destined to make it to the coveted First Class; however, a man named Zack Fair was.
Zack Fair was everything Cloud wanted to be: cool, confident and one hell of a fighter. He was friendly and liked by everyone he met with a First Class rank and a pretty girl waiting for him. In short, he was perfect. Even after seemingly achieving the impossible, Zack pushed further to trump the odds by befriending the young SOLDIER hopeful.
Cloud and Zack first bond over their backwater roots, and Zack quickly takes Cloud under his wing. However, their relationship is not merely one of a teacher and his pupil, as Zack treats Cloud as an equal--a true friend. Besides offering his help in the field, he stands up for Cloud when he's alienated from the rest of his unit, and even offers to give him an ear when he can't face the object of his affections. Cloud for his part listens to and admires Zack.
Shattered
The ultimate test for Cloud and Zack's friendship comes when their mission in Nibelheim ends in disaster. Cloud and Zack survived the violence, but were taken into custody by Shinra as the corporation frantically rushed to cover up the incident, finally being left in the hands of Shinra's scientific branch to be used as human guinea pigs. For years the two served as test subjects with nothing more than one another for support, ultimately strengthening Cloud's admiration for and bond with Zack. When the day finally came for their escape, Cloud was too weak to continue, but the virtuous Zack refused to leave him.
Zack was shot on the spot and Cloud was left for dead.
Such a violent ending to an otherwise perfect friendship pushed Cloud's flailing psyche over the edge. As he dies, Zack entrusts the Buster Sword in Cloud's hands, explaining that he gives more than a weapon for Cloud to carry.
Zack: Live. You'll be... my living legacy. My honor, my dreams, they're yours now.
Cloud: I'm your... living legacy...
Unfortunately, the affections with which Zack leaves Cloud are twisted by the traumatic events leading up to them. To Cloud, the one person who treated him with any sort of kindness -- the man he admired more than anyone -- was dead, and he was dead because he had protected Cloud. Zack was strong enough to leave on his own, but he voluntarily risked -- and lost -- everything to help his friend. This tore Cloud apart. If he failed his friend when it mattered most, than surely Cloud was worthless.
To remedy this, he takes Zack's request literally. He decides to act as a vessel for Zack's legacy to continue; he becomes Zack.
Picking up the pieces
Although eventually able to shake the persona, Cloud is still haunted by memories of Zack. The man had shown him nothing but kindness, and he had sat by and witnessed his murder. As he struggles with Geostigma -- more than two years after the man's death -- Cloud constantly finds himself coming back to the people he cared about most but could not save. He abandons the Buster Sword at the place of the hero's fall and takes to a life of solitude. However, even if Cloud is overwhelmed by his guilt, Zack himself holds nothing against him. In fact, he's more concerned for his friend than anything else.
Although he does not confront Cloud as Aeris does, Zack watches over him at the woman's side; he is heard joking with Aeris when Cloud falls into the Lifestream during the film Advent Children. He is not the guardian angel Aeris is -- he has no divine gift to offer the suffering people of the Planet -- but he's still Cloud's friend, a fact he has not forgotten.
Zack only visits Cloud once after his death; during the film's finale, both Zack and Aeris come to the church to check on the man they left behind for a final goodbye. He waits in the doorway while Aeris speaks with two young children attending her flowers and gives a casual wave when he catches Cloud's eye. There is something strikingly anticlimactic about the gesture; they were torn apart in a fit of violence, fueling Cloud's insanity and leading to months of mourning, and the only thing he can do when they finally see one another is wave? At the same time, however, it fits. Zack never saw Cloud as responsible for his death; he plays down his sacrifice because they're friends. He knows Cloud would have done the same for him. As a result, he maintains the casual, friendly air that drew Cloud to him in the first place.
Although this may be the last time they see each other, both silently understand that Zack will continue to stay by his side in spirit. After years of wandering the world in a misguided search for penance, Cloud realizes that sometimes that presence is enough.
a side note: why zack is not the wolf
I have both seen theories on other web sites and received numerous e-mails from visitors suggesting that Zack is actually Advent Children's lonely wolf. Although an interesting concept on paper, it does not play out in the film itself. As discussed on the Cloudy Wolf's page, the animal appears at three specific locations, each representing a different individual for whom Cloud feels tremendous responsibility:
- On the bluff by the rusted Buster Sword--the site of Zack's murder
- In Aeris' church alongside a fallen Cloud and Tifa (it is actually in the shot with them, suggesting it is meant to be associated with the present situation with Tifa, not the past with Aeris)
- Aeris' final resting place in the Forgotten Capital
Should Zack be the wolf, these three appearances coupled with Tifa, Denzel, and Barret's possession of Cloudy Wolf rings would impose his presence on personal areas of Cloud's heart where he has no business. Zack is very special to Cloud and a large part of the burden he carries, but he is not the whole of it as his presence as the wolf would suggest. Furthermore, making Zack the wolf would disrupt the flow of the finale; why should Zack get two goodbyes--one as a wolf and one as himself? This is in direct contrast with Cloud's belief that everything is precious, placing more importance on Zack than anything else in his life--past or present.
The theory of Zack being the wolf requires us to twist or otherwise overlook too many important images and even fairly straight-forward dialogue to be believable.
And to totally pull the Nomura Says card, he describes the wolf as being representative of Cloud's guilt in the film's commentary track (released with Advent Pieces). Sorry, kids.
