There were no skills in the battles whatsoever. Everything was resolved through pure speed, strength, and fighting style. The elders also made sure that no Divine Energy or Soul Power was used during the fights. Because of that, the show of lights and explosions that would normally happen couldn't be seen in the arenas.
In any case, it still served to show who could still hold on their own without the support of the skills they were so used to using. One of them was obviously Rean. After all, Roan made sure to prepare him for all possible situations, including ones where he didn't have access to his Divine Soul Power abilities.
'Death Style, First Form, Stellar Piercer!'
Rean's body shot forward like an arrow, piercing through the defense of his opponent. Although Roan's Death Style used Divine Soul Power and Elements, that didn't mean they couldn't be used without them.
*Bang!*