Cosmic Death Fungus

You create a 20-foot-radius sphere of glowing fungal spores centered on a point you can see within range.  The cloud spreads around corners, coats surfaces, and lingers in the air for the duration.  When a creature enters the cloud for the first time on a turn, or starts its turn there, that creature becomes coated in glowing spores.  

Attack rolls against a creature coated in glowing spores have advantage, and creatures coated in glowing spores have disadvantage on checks to avoid being seen.  A creature may use its action to remove glowing spores from itself or an ally within 5 ft.  At the end of its turn, a creature coated in glowing spores must make a Constitution saving throw, taking 2d4 necrotic damage on a failure, or half as much damage on a success, as the fungal spores grow into its body.

 A moderate wind (at least 10 miles per hour) disperses the cloud after 4 rounds. A strong wind (at least 20 miles per hour) disperses it after 1 round.