Marvel Comics Universe and X Of Swords Event Spoilers follows.
Externals – Not X-Ternals – Return In Excalibur #11! Mystery New Cover Coming?
Excalibur #11 is in stores on August 19, 2020, but may get a new cover considering it is the only issue missing on the main marvel site.
Anyhow, here is Marvel’s Externals tease.
The X-Ternals and later Externals were essentially immortal mutants aka High Lords; a kind of X-Illuminati.
Here‘s the X Of Swords event checklist so far.