In Another World With My Smartphone: Volume 12 by Patora Fuyuhara

Mochizuki Touya carries on his carefree life in another world, the looming birth of a wicked god and the peculiar behavior of the intelligent Phrase are no reason for him to panic! A distress call from a mysterious island forces him to jump into action, but what he discovers there may very well flip his entire world upside down... Pass through the open door to find a tale of swords, sorcery, and ancient legacies of antiquated mystery!