Loki (part 5): How Loki faked death with Thor and whole Asgardian??

After losing war against Avengers in London ,Thor took Loki and Tesseract with him. Thor then put Loki in prison and keep Tesseract safe in Odin vault.  Loki although was very in harsh condition in prison but by his magical powers ,he us een Happily inside it.

Then ,by this time , Jane foster the love of Thor has a terrible life. Aether ,the powerful reality Stone entered her body and she found strange in her body then Thor took her in Asgard. So, Malkeith took her from Asgard and  killed their mother. So , Thor reserrcuted Loki from prison to go Elves to deal with Malkeith. 

Loki surprisingly helped Thor and Jane foster using illusion and Thor sent Malkeith to another dimension. But during the war with Malkeith ,he faked dead there. And using disguise of gaurd their ,he entered Asgard  and sent Odin to out of contact from Asagrd and make himself as Odin and takeover the throne.