During the show, Grzesiek Czapla aka Gunslut from Woe/ex-Infernal Stronghold played drums during ABSU's first live performance of "Stone of Destiny" [not "Tara (Recapitulation)" as the article notes] while Proscriptor took on sole vocal duties. Proscriptor previously did a live lead vocal only performance for with Zemial during the song "Sleeping Under Tartarus" in 2011.
Songs featured in the video below:
Highland Tyrant Attack
Stone of Destiny
(In case the video above won't play for you, here is an alternative).