James wanted to finish the dragon off in just one hit, so he wished he could use a little bit of the finishing slash, which he couldn't quite manage.
The Wounding Pierce was too easy, but James was not sure if he could kill a dragon with it.
The dragon in front of them did not seem to be mature though, even Ariel's blades somehow managed to wound the dragon.
That meant that if James could somehow manage to use the finishing slash or unleash some small part of the power of that technique, he could kill or disable the dragon in a single blow.
James was well aware of this, he knew what he had to do, he realised what had to be done and that was why he had started to prepare.
He only had one chance, the dragon was destroying the chains one by one despite all the damage it was taking, Elise's magic would not have lasted that long, without Elise they would have been in a deadly battle.