Anything you want to store on entities, you have to do it using the following pev fields
Storing the data in arrays like you were trying is not safe, because entities can get very high indexes
Another good alternative is to use klippy's module which allows you to store data on entities
Also, don't use these fields on players
Code:
pev_iuser - for integers
pev_euser - for integers
pev_fuser - for floats
pev_vuser - for vectors
pev_noise - for strings