The truth is revealed in Episode 21 of Kamen Rider Gaim: The Secret of Yggdrasil.
Episode 21: The Secret of Yggdrasil
Writer: Gen Urobuchi
Director: Morota Satoshi
Earth will be destroyed by the Helheim Forest too.
Takatora has told Kōta the shocking truth. Kōta tells everything to Mitsuzane, also telling him that he cannot approve of how Yggdrassil wants everything covered up. However, Mitsuzane, being an Yggdrasil member already, strongly opposes his view and convinces him to just leave it.
Meanwhile, Kaito, using what seems to be a photograph, is looking for something in the Helheim forest. Someone’s eyes watch over his movements. Feeling the presence, Kaito transforms into Baron, but what is he looking for?
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