He was about to join the beta test on the newest VR games, Second World. But an anomaly threw him into a world with familiar rules, a rule he usually only experienced in a game. Now he must use his past gaming experience in this new world. It was no longer a game, it was survival! A strive to reach the highest level possible. Equipped with dual-class of melee and magic user, Jack was set on the path to become the strongest character in this brave new world.
Jack's HP continued to decrease as his soul was burnt. He couldn't do anything because his mind was a mess. The agony was a thousand times more painful than anything he had ever experienced.
Luckily, Peniel was not affected by the mental assault. She immediately used Invulnerability when Jack's HP went to critical.
The Invulnerability protected Jack from everything, including mind attacks. It cleared Jack's thoughts and broke the archdemon's hold on his mind.
But the aftereffect was still there. Jack's mind was slow in responding when the archdemon reformed his flaming saber and stabbed it into him. Fortunately, the invulnerability had not yet ended.
Jack finally got his shit together before the Invulnerability ended. He used Gold Dragon Vitality, recovering all his HP and also doubling his max HP.