C850 Five thunder descending curses

The tornado behind them was getting closer and closer. The three of them were getting more and more anxious. The tornado was starting to shake violently; it was obvious that they wouldn't be able to hold on for much longer.

"Lad, I don't know if you can cast the Five-Lightning Descent. If you can, then we will be safe."

"Five Thunder Descent Spell? I've never heard of it