Loki’s wants to take down the Avengers and the S.H.I.E.L.D. helicarrier, to disable the two greatest threats to his invading forces. To accomplish this, he lets himself get captured and the glaive taken away from him, knowing Banner would study it, fall prey to one of its terrible effects, become the ragemonster, and wreck the place.
That effect goes unnamed in the film so I’ll call it the bad mojo radiator. The longer people hang around it, the more discord it sows. In fact just before Loki’s thralls enact a daring rescue of him, we see all of the Avengers fighting in the lab, for no other reason than they stand in the glaive’s presence.
The infighting ends suddenly when Banner unintentionally takes the glaive in hand as he attempts to silence the group. Because the threat of Hulk + glaive is enough to make other fights seem secondary. Continue reading