each angel investor increases profit by 1% you can purchase upgrades that increase the %. When you soft reset you gain the angels which furthers your growth. You can sacrifice angels to buy upgrades which give you more bonuses to growth. Angel upgrades are worth it, so you make the sacrificed angels back in no time.
 "Idle Blacksmith"){kind=icon}
 "AdVenture Capitalist"){kind=icon}
 "Farm of Souls"){kind=icon}