Help in understanding mechanics

I have a few questions please. I am unable to find any meaningful answers on the internet.

1. What exactly does the Gilded Fossil (Item is overvalued by vendors" do? Are there any perks to this other than the item with this modifier sells more to vendors?

2. In the Atlas Skill tree I would like to focus on Einhart Red Beasts that are specific to The Deep and The Caverns. I have the passives "The Hunt for Fenumus" and "The Hunt for Craiceann" selected.

a. What does "Natural Selection" (Beasts in your Maps are more likely to be less common varieties) do? Will this better my odds for getting Red Beasts in The Deep and The Caverns?

b. What does "Great Migration" (Your Maps with Einhar Missions have 8% chance to contain additional Packs of Beasts instead of other Monsters) do? I have no idea what "other Monsters" are or if there are any benefits to this choice. Will this better my odds for getting Red Beasts in The Deep and The Caverns?

c. For my goal of getting Red beasts from The Deep and The Caverns, is it better to use a particular Scarab or an Einhar mission?

d. What are all the options/selections I would like to have to maximize my chance of getting Red beasts in The Caverns and The Deep?

I appreciate your assistance.

1. It has a couple uses. The first is what it says it does (it sells for more to vendors). It has cosmetic uses to put more modifier lines on an item. The most useful application is when you corrupt items. When you Vaal something and get a corrupted impliit, it doesn't replace all the implicits, it just selects one and replaces it. If you have an Astral Plate with the normal +all res implicit, apply a gilded fossil, and vaal it, you have a chance to get a corrupted implicit and leave the all res intact. (there might also be a use with synthesised items but not sure about this)

2a. It will not increase your chances of finding red beasts. It will increase your chances of finding rare beast types (like the Craicic Chimeral, and the ones you need to fight the bosses).

2b. Basically, one in every 12 maps will have a bunch of beasts in them. You should take this node because some of the extra beasts will be red.

2c. Scarabs guarantee an extra couple of red beasts, while Missions don't.

2d. Only your atlas passives and the scarabs you use affect these.

PurpleChakra,

Thank you very much!

That clears up a lot for me.

Now I understand.

Love the game and the support.