Family
Wavyern saw two incredible princesses when Twilight took him to the throne room of castle Canterlot. They looked in shock at the doorway when Wayvern walked in. He didn't expect Celestia to bow to him, and he certainly didn't expect a hug from her.
"It's been so long, Brother." At this, Luna and Twilight's jaws practically hit the dirt. "Tell me, how was your journey!? I want to know every detail!"
"That makes two of us." Wayvern said. Celestia looked confused.
"He doesn't remember anything but his name," Twilight said. "Which is why we came here, we thought you would know him… we were right apparently."
"Celestia… Why have I not heard of a brother before now?" Luna asked.
"Wayvern wanted to meet you after his journey," Celestia said. "He didn't want me to mention him to you until he got back."
"But if I'm your brother…" Wayvern put two and two together. "That makes me a-"
"The Rightful King of Equestria," Celestia finished for him.