this spell acts as a regular fireball, but upon expoloding everything in a 30ft radius is ingulfed in dark abyssal flame dealing 12d6 fire damage and 4d10 necrotic damage the oponnent must make a constitution saving throw, on a passed save take half damage, on a failed save the enemy takes full damage and id left with chilling feeling throughout their body halving ther movment speed and dealing 2d6 cold damage at the end of their turn. They can reapeat the save at the end of their turn.