Most of the Shasvastii troops in Code zone have the Shasvastii skill. The Caliban is an exception to this although they gain the skill in N4. Mistake? Oversight? Intentional?
What platform are you using? It’s listed on their profile in the iOS app. If it’s not showing for you, report it in the Army Bugs thread.
IT's not listed on the PC browser version nor in the Android app. Here's the bug report thread: https://forum.corvusbelli.com/threads/codeone-army-bugs.37068/page-3
It seems like they're in a different order on iOS and on a PC in either Edge or Chrome. On a PC it seems to be listed first, on iOS it's the 8th skill listed.