Ultimate Image

You create the image of an object, a creature, or some other visible phenomenon that is no larger than a 100-foot cube. The image appears at a spot that you can see and lasts for the duration. It seems completely real, including sounds, smells, and temperature appropriate to the thing depicted. You can't create sufficient heat or cold to cause damage, a sound loud enough to deal thunder damage or deafen a creature, or a smell that might sicken a creature (like a troglodyte's stench).

When you create the image, you can set a simple course of action for it to follow. The image will autonomously move and reshape itself in accordance with these instructions, and the spell's area of effect will remain centered around the image in a 100-foot cube when it moves. For instance, an image of a creature could be instructed to move towards and then attack a building, or an image of a storm cloud could be instructed to begin raining and flashing with lightning after 10 minutes. If you can see the image, you can use your action to directly control it or change the course of action you set for it. The image cannot move more than 100 feet in a round. If the image is ever more than 1 mile away its original location, it vanishes and the spell ends.

The image is a creation of your own mind and not a thinking entity; though it will act in accordance with your intentions, it cannot carry out complex tasks and cannot do anything which you could not make an illusion do, such as speak a language you don't know or eavesdrop on a conversation and relay the information back to you. When acting autonomously, the image cannot learn things you don't know, follow instructions that are not your own, or adjust its behavior in response to conditions you had not accounted for.

Any visible trace the image leaves on its environment becomes part of the illusion. For example, an image of a huge creature might leave illusory footprints, and an image of an inferno placed within a house might spread more illusory flames or be accompanied by illusory smoke. These residual illusory effects persist for 1 minute after they leave the image's area of effect.

Physical interaction with the image reveals it to be an illusion, because things can pass through it. A creature that uses its action to examine the image can determine that it is an illusion with a successful Intelligence (Investigation) check against your spell save DC. If a creature discerns the image or its residual illusory effects for what they are, the creature can see through all aspects of the illusion, and its other sensory qualities become faint to the creature.

At Higher Levels. When you cast this spell using a 9th level spell slot, the spell lasts until dispelled, without requiring your concentration.