In the end, Leon still could escape upward by using Transfer, but he decided to accept some risks. He didn't move at all and just used Mana-Eater on the mithril around his body in a crazy succession, much faster than his mana was being consumed to keep the Mana Barrier active in the middle of those hellish chain explosions.
Congratulations! The skill Mana Barrier has leveled up.
You obtained 01 status points.
Congratulations! The skill Mana-Eater has leveled up.
You obtained 01 status points.
Congratulations! The skill Mana-Eater has leveled up.
You obtained 01 status points.
Congratulations! The skill Mana Barrier has leveled up.
You obtained 01 status points.
...
"... What the hell are you doing? Why are you smiling?" Celsius said, and Leon imagined her frowning.
"Eh? I am smiling?" Leon said. "Don't know why... probably because I'm insane."