Book of Shadowflames

The Book of Shadowflames is a Hardmode magic weapon that fires homing Shadowflame projectiles. The projectilesare similar to Chlorophyte bullets in the way they look and home in on enemies - but purple of course. It inflicts the Shadowflame debuff for 5 seconds.

The Book of Shadowflames is The Shadow (Surface Biome) of the Hallow's Crystal Storm, the Crimson's Golden Shower and the Corruption's Cursed Flames.

Its best modifier is Mythical.

Crafting
It is crafted with: at a Bookcase.
 * 1 Spell Tome
 * 20 Shadowflame Cores
 * 15 Souls of Unbright

Tips
The Twins are the only mechanical bosses that are not immune to the Shadowflame debuff, so you should use the other spell tomes for the Destroyer and Skeletron Prime.