"Wow." Amelia was stunned. "How did you know?"
She was not that surprised to see Arnold kept on winning. Aside from her brother, who was simply a bug level existence, no one among them seemed to be able to beat him.
But Amelia was more surprised that Riya could tell that Ruben's mana is exhausted.
"Because his movement has become sluggish… The difference is faint and if you're not paying attention, you might not be able to see it. But when your mana is about to be exhausted, your speed of gathering mana to use your magic spells will decrease." Riya though for a moment before adding, "The difference is like 0,01 seconds, though."
Amelia: "…"
How the hell should she see it?
Seeing Amelia's speechless look, Riya just chuckled.
To be honest when Riya first learned about this from the temporary mentor in that world, she also had the look of disbelief. After all, the difference was fleeting and it was impossible for them to notice it.
