Hello i would us the regular bolt endcap for the Blizzard S10.
You will need this adapter to add a suppressor to this airgun.
Most evanix shrouds uses the same thread size for the adapter. This one should fit: https://donnyfl.com/products/evanix-rainstorm-1-2-x-20-unf-adapter-a29?_pos=2&_sid=b77d300ac&_ss=r