Domain expansion: lethal hallucinations

Create a bubble where the floor is water that can be walked on. To activate the spell the caster must hit the ground with whatever weapon or fists if they DO NOT have a weapon. The caster of the spell can modify the senses of anyone in the domain. At the start of anyone who is affected by the domain will have to make a wisdom saving throw with the minimum success roll being 16 or 17-18 at higher levels. If the NPC that is being affected does not roll the minimum, they will sink 1 and a half feet into the water, this will continue each time a turn of any character or NPC's turn passes until it becomes their turn again were they will make another saving through where if succeeded leave the illusion and be able to attack and do actions until their it becomes their turn again were if they do not meet the minimum dice roll they will return to the illusion and begin sinking again. The spell resets on a short rest.