Some items (usually those which you receive from friends as gifts) can't be sold, but can be sacrificed in the magical ritual to get some energy. Please note that the amount of energy you get depends on the level of the item. For example, if you sacrifice one Level 1 Ingregient case you will get 2 energy. But if you sacrifice one Level 2 Ingredient case you will get 4 energy, one Level 3 Ingredient case - 8 energy and so on.
To sacrifice an item click the 'Sacrifice' button and confirm your decision in the appeared dialog. Items will be taken and the energy will be given after the confirmation. Energy received from the ritual can exceed your maximum energy so no energy points will be wasted even if you sacrifice many items at once.