Brain Rot

You channel the corrupting forces of nature, reaching out to infect a creature's brain with a virulent affliction that gnaws at its mind. Make a melee spell attack against a creature with a brain within reach. On a hit, the target takes [roll]4d8[/roll] necrotic damage and must make a Constitution saving throw. On a failed save, the target becomes afflicted with one of the following effects.

Roll a D6 and consult the table below:

1-2: Parasitic Infestation - Writhing parasites burrow into the target's brain. At the start of each of its turns, the creature must make an intelligence saving throw. On a failed save, the target takes [roll]1d6[/roll] psychic damage and [roll]1d6[/roll] necrotic damage. You can use your reaction to force the creature to move up to half its speed. On a successful save the target takes half damage and suffers no additional effects.

3-4: Psychedelic Spores - Psychoactive spores invade the target's brain inducing hallucinatory visions. At the start of each of its turns, the target must make a wisdom saving throw. On a failed save the target takes [roll]1d6[/roll] acid damage and [roll]1d6[/roll] necrotic damage as it hallucinates its body melting, causing the creature to fall prone. On a successful save the target takes half damage and suffers no additional effects.

5-6: Neurotoxic Venom - A potent neurotoxin disrupts the target's nervous system and cortex. At the start of each of its turns the creature must make a Constitution saving throw. On a failed save the target takes [roll]1d6[/roll] poison damage and [roll]1d6[/roll] necrotic damage and has disadvantage on Constitution saving throws until the start of its next turn. On a successful save the target takes half damage and suffers no additional effects.

At the end of the afflicted creature's turns, it can make another Constitution saving throw with disadvantage if it also failed the saving throw against the affliction. On a success, the spell ends.

When the spell ends, the target gains a -2 penalty to the associated statistic against the rot effect. This penalty persists until the target is subjected to a healing spell or restoration spell.