- Final Fantasy VII
Cloud likely represented many people's first encounter with a truly believable and fallible video game character. He begins his journey under the façade of an abrupt and jaded war veteran. As the story unfolds, we see his true character emerge. It becomes clear that his cocky demeanour has acted as a defence mechanism for underlying emotions too difficult for Cloud to face.
I could write an essay psychoanalysing Cloud. He began life as a social outcast, frequently struggling with feelings of rejection. He had trouble finding his place in society. He only has any sort of tangible connection with one person - Tifa - and then it is just a casual association. After being blamed for her accident, Cloud becomes even more reclusive. He fantasises about becoming a powerful figure like Sephiroth, to the point of idolising him. To a young Cloud, Sephiroth represents everything he could desire to be, and with his loose understanding of social dynamics and his chronic feelings of inadequacy it is difficult for him to live a realistic version of his own life, even back then. The distress of acknowledging how unhappy he is with himself would have been devastating. Ultimately, Cloud decides to join SOLDIER - likely a last ditch attempt at finding purpose, place and affirmation in the world.
Unfortunately, he fails at this too, and we watch an epitomal scene unfold. Sephiroth represents an idolised version of Cloud himself, one which he has relied on for strength of character and motivation to achieve more. Zack is a direct superior, a man for whom he holds a deep respect - and who perhaps provided Cloud's first ever true friendship. Sephiroth killing Zack would have been intolerable or even truly unbearable for Cloud. His idealist support system has destroyed his only realistic progress he has made toward the life he wanted. At this point it is predictable that Cloud would have unravelled, without any foundations left for his own stability to hang on to.
When Cloud assumes Zack's character, he is psychologically defending himself from falling apart. If he is Zack, then Sephiroth didn't kill Zack; his only friend didn't die; and Cloud wasn't a failure within SOLDIER. If he is Zack, then his world hasn't been destroyed around him. It is the only thing left for him to do.
I do not believe that he has schizophrenia. He doesn't have any of the negative symptoms or disorganisation. However, he could be in a Dissociative State, forged for his own protection. It is a historically documented condition which has been most commonly seen in victims of severe trauma and war violence.
Cloud continues this way for an unknown period of time. He forges a group of comrades - real life, genuine friends. He finds a place in society. He ends up, despite being in the middle of a worldwide conflict and in direct opposition to Sephiroth, in the best psychological position he has ever had. There is a real significance to the act of giving Sephiroth the materia; Sephiroth still has a control over him, but Cloud is starting to realise that it isn't sustainable. He continues to grow, to understand love and support. At this point, he no longer needs the crutch that assuming Zack's identity has provided for him. In any case, the truth of his character is revealed and in one fell swoop he sacrifices his dependence on both Sephiroth and Zack.
It is unsurprising that Cloud would enter a catatonic state. But it is also a huge testament to his strength that once again he is able to get out of it, accepting the help of his friend. He completes the game more himself than ever before and embracing the reality of what it is to be Cloud Strife.
"It's not my problem."
"A sealed up, secret wish. Tender feelings... no one can ever know."
"I'm... Cloud. The master of my own illusionary world."