Eternal of Legends

1. First, you need to find a Spellbook. Reference: ⁠Where Can i find a spell book?

1. After completing Main Quest 4, you will receive the Arcane Codex as a reward.

1. Place the Arcane Codex anywhere you want. Please note that it is quite large, so make sure you have enough space.

1. Right-click the Arcane Codex to open it.

1. Put your used Spellbook into the right slot.

1. Press R to register the spell.

1. After that, you can cast the spell!

Note: The Spellbook placed inside the Arcane Codex must be a used Spellbook.