Marina started to understand more about Eren as their duel went on.
She realized a huge anomaly when it came to her enemy. His A-Rank mana was not running out despite the fact that he was using them to empower his intent-based spells.
It was as if Eren had more than enough mana stashed somewhere that enabled him to fight on par with an S-Ranked dragon without having to worry about his mana expenditure.
'How can a mere grandmaster Ranker have so much mana at his disposal. He is just showing off at this point. There's some trick involved. Wait a minute. Is... Is he trying to buy time? What else has he planned?'
After engaging with Eren in close combat for several intense rounds, Marina leapt back and landed a few meters away from him. She realized that she was inadvertently influenced by his pace.
She decided it was time to stop toying with her prey and unleash her true draconic power to kill Eren in the most brutal way possible.
'Oh! It seems she noticed that I was trying to buy time! This dragoness is indeed smart. Kekeke. I'll see if I can get her to obey me. It'd be pretty cool to have someone like her by my side,' the butcher thought to himself.
The seven-fold mana core had given him all the confidence and assurance he needed to face someone like Marina. It wasn't that he had become invincible in front of all S-Ranked entities. However, it gave him a fighting chance against them. And that's what the butcher needed to turn the tides in his favor.
'Hmm. She is up to something.'
Eren watched with a mixture of curiosity and excitement as Marina's form began to change. Her already formidable presence grew even more imposing.
Scales started to appear, covering her arms and legs with a gleaming, iridescent armor that shimmered. The scales, tough and impenetrable, gave her a fearsome appearance.
Two horns on her head began to elongate, twisting and curling into an even more intimidating shape. The draconic runes etched over the horns glowed with a faint, otherworldly light. Her eyes turned into slits, radiating a piercing, almost hypnotic gaze.
***
Roar!
With a roar that shook the very air around them, Marina launched herself at Eren, her draconic features fully unleashed. Her spell-casting speed and efficiency improved to new levels, enabling her to make use of her go-to spells with just a thought alone.
She moved with incredible speed, her claws slashing through the air with deadly precision. Her tail whipped around, aiming to strike Eren from multiple angles.
"Let me see what the overhyped lizards are made of. Kekeke."
Eren met her onslaught head-on. He wielded Asura with expert skill, parrying her strikes and countering with his own. He imbued the weapon with Wrath Mana, which agitated Demonmir's trapped soul and improved the Elder Seed's Artifact's raw power.
Screeeee!
The saber screeched in protest, but Eren's grip was firm. He was forced to use his divine powers once again, which started taking a toll on his body.
Marina was finally able to make Eren fight with all that he got. Almost. Their battle changed the landscape of the entire island and affected the surroundings in ways that were beyond a mortal's understanding. It was as if two giants were busy quarreling with each other and destroying everything in their wake in the process.
The battlefield became a blur of motion once more, the clash of divine power and draconic might creating shockwaves that rippled through the island and stirred the sea into a tempest.
Eren's playful grin never wavered, even as he faced the full fury of Marina's draconic form.
Even though he had several internal injuries due to his own God Spark harming him, he managed to wipe the blood from the corner of his lips and smile.