War of the Chosen and alien alloys/elerium crystals

[CYBRED]

Besides excavation how do you get alien alloys and how do you get crystals?

[Abrakadabra]

There's a few ways:

Supply raids: Standard supply run like in xcom 2 vanilla, no timer, so pretty relaxed missions

Supply extraction: harder missiosn, you gotta try to mark each crate individually and advent will extract them too if you dont hurry.

And you can buy those things via black market, check at the start of each new month. You can also sometimes scan for either one of them or both even.

[CYBRED]

When does the black market show up in war?

[Mr. Nice]

Pretty early, before you have any use for alloys and definitely elerium.