Loki's eyes darkened, filling with pure, unadulterated malice. He has has quite enough of losing to people not worth his time, so he makes a calculated decision. With a burst of energy the door blew from its hinges, ricocheting off the walls and falling the floor with an shrill clang. Loki stepped out into the hallway calmly, stepping over the door he began to walk with a definite swagger.
If he couldn't kill the one, why not kill them all? He would bring the building crashing down around them and crush them beneath it's almighty weight. Like crushing an ant beneath his boot.
"You had sealed your fate mortal" He shouted, making a parting jab at the agent before he teleported.
When Loki appeared again it was in the very base of the cube, he would bring it down from it's very foundations. He walked around what looked like a central pillar and stroked it thoughtfully. He sometimes wished he was gifted with Thor's strength to wield Mjolnir, the satisfaction he would get from crushing the building using his strength alone. However Loki was gifted with other powers, his Seidr would allow him to not only bring the building to rubble but to watch as it did.
Using all his concentration Loki summoned what looked like a bright red ball of gleeming energy. However, instead of throwing it, he placed it at the pillars base and watched it begin to grow. The red light swirled and began to grow bigger in its place, then with a crack, the pillar began to fragment. With one last smile Loki Teleported.