All about money..
How to get 4* new champ from every 150 unit crystal.. i know one player who spend more than 50k rupees in enery month.. he hv worst skill and need to buy unit every day.. bt he hv all new 4* character.. today he opend 3 crystal and got 3 new 4* champ.. 90% time he got 4* frm phc... so i think its all about your monthly money expenditure.. spend u lot.. and kabam gives u more chances to get 4* from phc and featured hero crystal...