Aster felt the happiness Sarina was radiating right now and he inwardly sighed, as the maiden of the star she knew the ability she got, so she was clearly in cloud nine after seeing she could use that golden light, she has seen him using.
"Now that I think about it, I haven't explained them how my attribute works… that was my mistake", he thought.
He didn't hide it on purpose though, Sarina and Kana haven't asked him about annihilation, if anything Kana liked to see how he used the golden armor, so she probably thought annihilation was the "sword" of the armor.
But now that Sarina could use it to some extent it was better to explain her how it worked, although star maidens weren't affected by the abilities of each other, there were four girls in the group which weren't star maidens, Kana, Eris, Mylene and lastly Camila.
