User blog comment:Jopjopjop/SlashDog/@comment-73.46.6.122-20150615203910/@comment-3965848-20150615215500

Avatar types are basically SG where one summons an animal/beast that has it on mind and opinion, it could probably even disobey it's user.

In chapter 2 above it says that Utsusmis are something "artificial" that can copy other Avatar type SG.