Hiccup and Toothless become a dual Heroic spirit, and are summoned by Chaldea.

Possible other introductions, Fuyuki, or Servant from Orleans.

Hiccup Haddock Horrendous III and Toothless the Nightfury
Class: Ruler
Max Riding skill
Max Taming Skill
Max Crafting Skill
Dragonic Charisma(ability to attract both allies and enemy's, mostly Allies and love interests though)

Able to calm calm Madness enhancements.

Charm EX(increase Attack and Hit count greatly for all allies(3 turns)

Sarcasm A+(invincibility for 3 turns)

Heart of a Chief and Soul of a Dragon(Guts(5 turns) for all allies and has 2/3 chance to restores HP to max)

Able to calm the most dangerous of beasts, be they monsters, or of the Beast Class(like Tiamat). Can subdue nearly any foe with out killing.