Riven simply did not want a war to interrupt his time with Ronan, that was it... Wasn't it? That was why he helped.
Though Riven would not admit it, Eli's words got to him. He helped, and that made him happy. He prevented things from getting worse. Civilians did not have to suffer the consequences of an internal war.
Riven and Eli continued their conversation, the air between them becoming light as they swapped stories and shared laughter. But soon enough, Eli had to leave, reminding Riven to take care of himself as he walked out the door.
As soon as Eli was gone, Riven felt a little more restless. He was about to wander the manor, maybe go out, when Troy's voice rang out, firm and unyielding. "Riven! Back to your room."
Riven completely ignored Eli's advice, he did not want to stay cooped up in his room! Nothing ever happened in his room! Everything happens out there in the world and he did not want to miss it.
"Wait, what?" Riven protested, eyes wide. "I was just going to—"