Tainted Blood

Using an action you take 2d10 of damage, and an target you can see must make a constitution saving throw. On a successful save the spell does nothing and you still take the damage. On a failed save the target now has disadvantage on all constitution checks/saves, and you can choose from the following effects.

Muscle Apathy

The target's strength score is reduced by half rounding down

Lethargy

The target's dexterity score is reduced by half rounding down

Weakened Mind

The target's intelligence score is reduced by half rounding down

If the targets score is reduced to 0 then the target incapacitated for the duration of the spell. The target may make a constitution saving throw at the end of its turn to remove the spell.