Leonel hadn't expected to end up as injured as he had during the first battle. He planned to use the trio of beasts as a whetstone, but had ultimately ended up suffering from success.
The result was that Blackstar had used up all of his stamina and Leonel could only send him into the Segmented Cube, and now even Leonel himself had to retract his Divine Armor.
It had been a very long time since Leonel's Divine Armors had a stamina drain on him, but it also had to be remembered that one of his uncle's go-to methods of training was perpetually keeping his Divine Armor active.
Leonel had seen this once before, and his uncle had ended up taking it off just so he could see the avalanche of sweat beneath.