Tal'mere's Eldritch Plague

Reality bends around creature of your choice within range, causing a nightmarish affliction upon them. The target must succeed on a wisdom saving throw or have insects and slugs crawl out of their mouth and ears, suffer hallucinations, or any other traumatic effect of your choice that doesn't physically harm them. While the effects of this spell are active, the target is stunned. At the end of each of its turns, and each time it takes damage, the target can make another Wisdom saving throw. On a success, the spell ends. If the spell's duration passes without the target succeeding any of the saving throws, the target gains short term madness.