Arcane Absorption Grenade

This strange mechanical device has a gem in the center that is revealed when a creature uses an action to ready the grenade. As a reaction, the user can use it to absorb a spell or other magical effect within the grenade that targets them or a creature or area within 15 ft. of them unless they throw it at the effect or spell. The device can only store one effect or spell at a time, and it must be used before a new one can be absorbed. The grenade cannot absorb breath attacks from magical creatures, such as a dragon's breath attack.  

If the grenade is storing a spell or magical effect, the user can use its action to direct it at an enemy. The effect is treated as though it is being used from the grenade, not the user. If it targets one enemy, the user can simply point it at whatever they want to effect and use it. If the effect or spell is an area of effect, such as Fireball, the grenade must be thrown. 

Each time a spell or effect is absorbed or used, the user must roll a d20. On a 1, the grenade breaks and activates the effect on the user. A single target effect only affects the user, while an area of effect spell or attack is then centered on them. Cone and line effects are fired in a random direction, determined by the DM.