Ymir's Flesh
The essence of the mythical giant Ymir, from whose flesh the world was created. Ymir's Flesh can be obtained from special deposits or found in chests in various locations all over the Frail World.
Magical extractors allow turning Ymir's Flesh into Ymir's Spirit. Extractors can be bought from the trader in the Gate Between Worlds location.
Also, the shaman in the Gate Between Worlds location is willing to accept Ymir's Flesh in exchange for prizes.
Ymir's Spirit
A magical extract, the power of which holds the worlds together. Ymir's Spirit is obtained with special extractors sold by the trader in the Gate Between Worlds location.
The more Ymir's Spirit you have, the higher your rank in the Tournament of Immortals in the Frail World.
Ratatoskr in the Gate Between Worlds location will allow you to transfer part of the Spirit to the main world, but remember, the transferred Spirit will turn into silver when a new portal to the Frail World opens