He has a history with Odin, who had barred him from entering Asgard. Upon finding out that Odin is on Earth, Mangog interrupts Odin's duel with the Avengers in order to take revenge on Odin. Odin manages to hold his own against Mangog until he managed to knock Odin down. Mangog then takes Odin's Gungir in order to combine it with his own weapon. Thor and the rest of the Avengers had to work to disarm Mangog of his weapon. Once that was done, Odin reclaims Gungir and has Heimdall open a portal to send Mangog to another location. Before disappearing into the portal, Mangog still plans to get revenge on Odin.