Things we see in Crisis Core that show Zack’s love for Cloud.

1: Zack dying to protect Cloud.

2: Zack protecting comatose Cloud for over a year.

3: Zack constantly encouraging Cloud .

Things we aren’t shown but defiantly happened.

1: Zack having to wash and change Cloud over the course of the year.

2: Zack cutting Cloud’s hair the way he likes it.

3: Zack feeding Cloud three meals a day, sometimes having to forgo a meal himself because he couldn’t get enough food.

4: Zack Having to massage and exercise Clouds muscles to prevent Atrophy. 

5: Zack having to help Cloud go to the toilet.

6: Zack having to make sure Cloud is protected from the elements whilst they sleep.

7: Zack crying because he misses Clouds voice, and because he isn’t sure that Cloud will ever be the same again.