Can limited time players only be pulled from special packs?

Im wondering if the limitedd characters they drop every weekend are available in all packs or just their limited packs. for example can i pull this palace guard from an elite pack or only the Theron packs(or whatever there called)

Only craftable cards can be pulled from the standard packs (Elite; Operations; Horde; Versus).

All of the special non-craftable packs are only available from their specific pack. These cards are often eventually added to the launch range though, so Skorge and Myrrah for example. This happens once per month where a set of cards is chosen and added.

Specifically for your post, the cards in the Palace Guard range are only available through the Palace Guard pack.