When Rin awoke, he was explained the current situation.

"An everlasting pact?" Rin repeated.

"Yes. That means that I will serve you forever. At least until one of us dies. I shall remain your faithful butler," Sebastian said, bowing.

"No way. I don't wanna be stuck with you forever," Rin responded.

"Think about the children, your friends, even my young Master..."

Rin sighed in defeat, "What do I have to do?"

After Sebastian explained what to do, Rin held out his hand and closed his eyes, wanting power. He could feel something deep inside of himself but didn't know what. Suddenly, a burning pain erupted on his hand and Rin opened his eyes to see a red Seal mark that was similar to Oga's on him.
"Good job Master Rin. Now all you have to do is trust me," Sebastian said, taking Rin's Hand.

Sebastian removed both of his gloves and placed one of his hands on top of Rin's. After a few moments, Sebastian's hand had an identical mark to Rin's.

Sebastian's eyes flashed crimson as he turned his attention to the barrier. Placing the hand that had Rin's seal mark on the barrier, Sebastian took a deep breath as a larger version of the mark appeared on the barrier. Sebastian then punched the barrier.

There was a rippling from the impact and the entire ground rumbled. There were blue flickering scorch marks left by the impacted.

"The barrier is destroyed," Sebastian said.

"Good," Rin said, placing his hand on his head. "We should go save them now," he said, wobbling a bit before falling into Sebastian's arms.

"Master Rin, whenever I use your seal mark I am borrowing your power. This is the first one I've done so, therefore it's alright to be tired. You can rest here-"

"I'm fine! I gotta rescue William and Isaac..."

Sebastian held Rin and began to follow after Sadao, Emi and Gilbert who had already proceeded to enter the building.