Instructions
Ensure that your innocent Devil-type ID is not at the base level and has already been upgraded to "Brow" status before attempting to upgrade it to its final, post-Brow state. Each upgrade state must happen individually in a linear fashion. Ensure that the innocent Devil-type ID has been properly upgraded to the first stage by obtaining 200 evo (evolution) crystals while using any weapon. Crystals can be obtained by fighting and killing the game's enemies, which will drop them at random. If you are lacking in crystals, backtrack in different levels and make sure that you have killed every potential enemy in order to collect the 200 evo crystals necessary to power up your Devil-type ID and evolve them to the "Brow" state.
Make a Trident if you do not have one already. Gather the following items from enemies and from within the levels to create the Trident: one Sasumata, one Ether and one Aquamarine. You can pick these items up when they are dropped by running over them.
Make a Versatile Spear if you do not have one already. Create the spear by first gathering the following items from downed enemies around the game world: one Trident item, one Naginata, one Ether and one Phlogiston.
Make the Devil's Vein with one collected Sasumata and one Steel.
Create the Dark Crystal using one Ceremonial Tool and one Spirit of Fuji.
Ensure you have the Chauve-Souris (Isaac's Spear) weapon in your possession and equipped before attempting to evolve your Devil-type ID beyond the "Brow" stage. This weapon must be used to kill any enemies going forward if you wish to evolve. You will need the Trident, the Versatile Spear, the Devil's Vein, and the Dark Crystal items in order to make the Chauve-Souris weapon. Once you have this weapon, you may move forward.
Use the Chauve-Souris to kill enemies and collect another 100 evo crystals. You cannot collect these crystals with any other weapon if you wish to evolve. This will evolve your Innocent Devil Brow into its final form.