...…
Bang! Bang!
Owen was first having a hard time keeping up with Arthur and Leonard as Shin and Diablo were purposely letting him train under such pressure. Those two were only appearing at crucial times that could lead to Owen's death.
But after the constant exchanges, Owen regained his confidence and started fighting properly, especially when Arthur and Leonard were not giving Samael any attention.
The two were very familiar with Shin and understood what this brother of theirs was planning. This was why they welcomed the 'roles' he had 'given' them and fought just like that.
They let Samael do whatever he wanted while putting as much pressure on Owen. Of course, they were still annoyed with the constant harassment that Shin and Diablo were giving them.
This led the two to reveal one of the trump cards that they were preparing for future battles.
Swoosh!