Spar

"Lunch and then sparring," Samuel replied. "Most of them have similar strength, but if you do want to participate, I would like to ask you to limit yourself."

After all, Riya's real rank should be rank 4.

This was Samuel's conjecture based on Riya's performance so far. 

The magic spells that Riya used in that crack and the large number of magic spells that she used… it had to be rank 4. Because between rank 3 to rank 4, there would be a large improvement for a magician.

The same is true for magic warriors and warriors, but the details were different for each of them. 

For magician, the amount of mana they could use would increase almost tenfold when they reached rank 4… So they could use the magic spells below rank 4 with ease without the need to worry about lacking in mana. And the magic spell rank 4 would also require much more mana.