Just a Little about sainting:

sainting limit:
Blue heroes: Angel 5 (15 sainting lvls)
Purple heroes: Archangel 5 (20 sainting lvls)
Gold heroes: Dominion 5 (25 sainting lvls)
Main Hero: Seraph 5 (30 sainting lvls)

More cards can be used to increase the chance of sainting succes up untill Archangel 5.

Sainting bonus:
white bonuses < Blue bonuses < purple bonuses < gold bonuses
When sainting the better quality a hero got, the higher the chances of a high lvl ability. In example gold heroes wont get white bonuses.

Unwanted bonuses can be removed from a hero with gems. However the cost of this increases when sainting lvl increases