Thank youuu for those chapters. They are great.
In case god can't crack that dragons shall, Mitsuwa can still teleport to everywhere she wants to. She just needs to bring high yield explosives to the dragon's body. In an extreme case she could solve a Claymore mine into its ass.
Edit: I don't know if I remember correctly, but isn't she also able to teleport small objects short distances? Image she would teleport onto its nose and than arm and teleport a handgrenade into its brain. Worst manmade stroke imaginable.