Since the first day of its creation, Sebastian's Leviathon body never left the sights of his main body due to the importance that this body had to him.
At first, the main body took it around like a fragile perishable good but this assumption stopped after the Leviathon fought its first official battle.
After that battle, Sebastian fully understood the capabilities of his ultimate war vessel but this didn't prevent him from keeping it close to his main body still.
For some reason, back then, Sebastian felt that it was not time yet to let his ultimate war vessel go out on a rampage.
That was then though, now, the Leviathon finally experienced freedom.
The piece of Sebastian's mind that resided inside the Leviathon heaved a sigh of relief as he finally experienced freedom for the first time in his life.