Is the Palace of the Dragon King a jutsu or a space dimension

king dragon jituLava dragons are former red dragons that have been transformed after being surrounded by lava for too long.[1] They reside in the Lava Dragon Isle in the Wilderness (between levelThe Sharingan Revived: Dragon-Flame Jutsu! (れ!・の!, Yomaere Sharingan! Hissatsu: Katon Ryūka no Jutsu!) is episode 30 of the orinal anime.