Vincent can issue three challenges and he has to carefully select them.
Luckily, he already gathered information about the participants of this event.
It was also a good thing that the rule allows them to select any participant. Without thinking too much of it, he issued challenges against the three strongest students. They were Alexander, Elena, and Magnus respectively.
The organizers of the event would then schedule these challenges accordingly so there wouldn't be a conflict with the others. Fortunately, they were allowed to challenge these three a total of ten times.
In the first few rounds of battles, Magnus hasn't participated in the duel yet as most of the participants were aware of their limits. Even if they're thinking of challenging him, they are planning of doing it with their last challenge attempt if there is still a chance.