Perhaps Zack's and Aerith's deaths...

Cloud actually has a pretty good sense of humor when he uses it, though.

In Dirge of Cerberus, Cloud was happier, akin to his FFVII counterpart, but his outfit remained the same as in AC. Perhaps in the next installment in the related compilation, perhaps Cloud's outfit can be more colorful, with stripes of brown, purple, green, and orange.