Spreading Spores

At 10th level, you gain the ability to seed an area with deadly spores. As a bonus action while your Symbiotic Entity feature is active, you can hurl spores up to 30 feet away, where they swirl in a 10-foot cube for 1 minute. The spores disappear early if you use this feature again, if you dismiss them as a bonus action, or if your Symbiotic Entity feature is no longer active.

Whenever a creature moves into the cube or starts its turn there, that creature takes your Halo of Spores damage, unless the creature succeeds on a Constitution saving throw against your spell save DC. A creature can take this damage no more than once per turn.

While the cube of spores persists, you can't use your Halo of Spores reaction.