Originally posted by The Sorrow
It looked as though he used it as a conductor and amped his lightning, it showed a close up of the building and his lightning flowing through the tower and then he channeled it through himself. Makes sense iirc his lightning was never that destructive even in his own film and why cling to the building when he could have just as easily used his flight.
Yea, I just re-watched the scene and the lightning was channeled directly into Mjolnir, and then directed at the invading aliens.
I'm not sure how the building would have amped the attack. It was lit up, but because of the excess lightning traveling through Thor/Mjolnir and into the building.
Also, I never noticed how huge the blast was. Right before we cut away, the bolt had grown so big it was comparable to the Leviathan in size.
Maybe landing on the building was more comfortable or made the whole thing easier, not sure.