did Yggdrasil use vines with thorns on Masaru?

that must have been painful and probably left some marks on Masaru

Nah I tried making them round bc they're just leaves :)) He himself won't hurt Masaru, Chika, or Sayuri; if his kids end up in situations that are dangerous, he would only intervene if it was absolutely dire, because those are their actions and choices. But he himself won't be harmful; he's a god, he can restrain Masaru without causing him harm.