Confirm the Illuminati

Vim, 40 bytes

-2 bytes thanks to DJMcMayhem

9i_|␛r\I/␛qqYPxR /␛q8@qr^4jhR/o\␛jr/2hr\

You can see it in action in this GIF made using Lynn's python script

Charcoal, 25 21 bytes

Ｇ¬χ|_¶_|↗⁹↙^Ｍ³↓/o¶\‖Ｂ

Try it online! Link is to verbose version of code. Explanation:

  χ                     With sides of length 10
 ¬                      In the directions down and left
Ｇ                       Draw a closed polygon (implicit side)
   |_¶_|                Filled with |_ and _| on alternate lines
        ↗⁹               Draw a line of 9 /s
          ↙^            Draw a ^ and move the cursor down and left
            Ｍ³↓         Move down 3 characters
               /o¶\     Print the left half of the eye
                   ‖Ｂ  Reflect the canvas keeping the right edge

SOGL V0.12, 31 27 25 bytes

 ^9∫Ƨ_|m└Κ}¹±§"/o¶\_”95žΓ

Try it Here!

 ^                         push "^"
  9∫      }                do 9 times, pushing counter
    Ƨ_|                      push "_|"
       m                     mold that to the counter
        └Κ                   prepend "/"
           ¹               collect the lines in an array - ["^", "/_", "/_|", ..., "/_|_|_|_|_"]
            ±              reverse each                    ["^", "_/", "|_/", ..., "_|_|_|_|_/"]
             §             reverse as ascii-art:
                            ["         ^",
                             "        /_",
                             "       /_|",
                             ...,
                             "/_|_|_|_|_"]
              "/o¶\_”      push "/o
                                 \_"
                     95ž   insert that at [9; 5]
                        Γ  palindromize horizontally

or a 24 byte version using ¼ (space to an antidiagonal) instead of ±§:

 ^9∫Ƨ_|m└Κ}¹¼"/o¶\_”95žΓ

Try it Here!