The prompt for the invite appeared before him as he stood there in front of Thessalia. With a nod he'd accept the invite and would be added to Party F of the Raid group. Bringing his hands to the back of his head with his elbows pointed into the air, a light laugh would escape his lips as he heard her say something about not always partying up together. "I know we don't always party up together, it was just a joke seeing as we do quite often when it comes to Boss Fights." He'd say to her, trying to keep the smile on his face as he saw the mood of her expression changing to that of a dimmer one. RievaX had wondered if it could be something he said that would cause her expression to change so noticeably, the smile on his face going away slightly - but not disappearing.
Before long the mask of a smile would have faded from his face completely. Despite being a rather upbeat person most of the time, ReivaX used his smile to hide the fact that he'd become increasingly more afraid of the chance that him or anyone he'd become friends with in SAO could die at a moments notice. The floors were getting harder and harder to clear and there were less and less frontliners with each passing Boss Fight. The thought that death was a real possibility that could happen at anytime in this "game" tormented him continuously, but he knew he'd have to fight to get out of this hell hole no matter what the outcome may be - even if it meant having to watch his friends die one by one or die himself, he had to fight.
As Thessalia looked back up at him, he put the wide toothed smile back on his face. A look of question soon replaced the smile on his face when he heard her say there was one party rule, One rule... I wonder what that could be? He thought to himself, only to have his question answered moments later. "No dying? Aww, damn it. That's the first thing I was going to do." The joking tone obviously present in his words, the smile on his face growing even more. He would place his hand on Thessalia's shoulder as he looked to her before speaking, "Don't worry, I don't plan on dying anytime soon, we still have to make it out of here." The tone in his voice was serious for a change and the smile no longer present as he spoke, he wanted to make it clear that he wasn't going to die on her during the Boss Fight. "That goes for you too okay? No dying... you have to make it out as well." He added, taking his hand off her shoulder and holding it at head height between them with a confident look in his eyes, he waited for her to shake his hand as if to confirm neither of them were going to die in this Raid.