Levi.
Crimson Emperor Dragon Breathing Technique: Level 13 (1/400,000), Special Effect: True Form of the Fire Dragon (Level 1).
...
"After this grand fusion, is there only one special effect?" Levi looked at the empty panel, feeling a bit uneasy for a moment.
True Form of the Fire Dragon: Crimson Emperor Dragon, Flame Dragon of World Annihilation, the Incarnation of Strength. You have initially awakened the true form of the Flame Dragon during the Crimson Emperor Dragon's juvenile years.
Having a normalized Flame Dragon true form grants you an extraordinary affinity for flames, unparalleled strength, strong resistance to fire-element spells, and a Dragon Flame attack capable of incinerating everything.