those are Perks. there are 6 of them. when you reach Character level 99, click on the Shop Tab, and on the General Tab, at the bottom right after the Gold Purchases, there is a button you can click on that gives you a choice of 6 Perks to choose from, but you need 5 million Gold to do the first one. if it is greyed out, your level is too low to click on it.
here is a Patch Note that explains what each Perk does.
some Players don’t get the Perks because they don’t want or need them, but for those Players who want them, they help with Farming and getting Loot & Rewards.
the down side for getting Perks is that after getting a Perk, you get reset to Level 1. your Items get put in your Inventory until you are a high enough level to equip them again. your Stats go back to level 1, but your Hero Points are unaffected. also, the experience needed to level up goes up 2x or more depending on how many Perks you go for.
when you have a Perk, it will say Active. when you have a Main & Hireling, any Perks that are active on the Main will be Active for the Hireling also. if the Hireling has Perks, they will be Inactive, except for the Dealer Perk. if the Hireling has the Dealer Perk, but the Main does not, only the Hireling gets the benefit of the Dealer Perk.
hope this helps.