Fallen mermaid's spell

The sword gave off a blinding glow as he swung it down onto the water. The whole water started to glow and as john cast deprehendre 

He noticed that the number of fallen mermaids who were within the glow's radius, were dropping. The 8 mermaids that charged straight at them disappeared. 

Almost as if they were evaporated, John could no longer feel their presence. 

As for the other fallen mermaids, they were keeping away from the light. John who noticed this quickly asked 

"How long can you last?" 

"I'm not exactly sure, but I'd say 2 more minutes." Richart replied 

"Please hold out for that long." 

"Understood, I'll do everything in my power to meet your expectations." Said Richart 

"Thank you." Said john 

He then turned towards those who were supporting the swimmers and shouted