What happens when the illusion is attacked or takes damage? At 5th level, you would expect it to stick around and appear to be a corpse of yourself, right?

Is anyone reminded of stealth elf from sky landers when they look at this spell?

Illusory. No. It’s just an image and has no physical form. Nearly all illusion based spells operate this way. 

My take, this duplicate is illusory, not physical.  It cannot physically affect the environment.  And the environment does not physically affect it.  Objects pass through it, and it passes through objects.

However, unlike several other illusion spells, physical interaction with it does not reveal it to be illusion.  Yes, objects pass through it, and one might ASSUME it's an illusion, but it could also be a ghost, or you under the effects of a spell that causes you to be incorporeal.  The image does not become faded and see through.  And others cannot make an investigation check to see through it, though they could determine that it isn't affecting/affected by the environment and make their own mind up.

This is important.  If a foe loses line of sight on the duplicate, it can't be sure that it's seeing you or an illusion the next time it sees the duplicate.

Movement is a tough one.  I would allow the illusion to pass through objects and move in any direction.  It's a great scouting spell, but also has great applicability in role playing scenes.  I personally don't have issues with my players finding out details about the dungeon ahead of time; I will simply adjust things to keep it interesting for them.

Quote from AshtonSurespell >>

I feel like this fits the trickery domain better than twilight. Thoughts? 

 Yeah it's kinda weird that trickery domain doesn't get it.

As an illusion. 

This is a fun spell to give as a legendary action along with some movement or to give a monster at will in place of it's normal at will invisible. It's a fun combat twist for a monster and is not so much more powerful in combat than invisibility that you should worry about letting monsters cast mislead as much as invisibility.

Some other things to note is since it is somatic only an enemy only knows you cast a spell if it sees you when you cast it and if you cast this using subtle spell it is impossible to detect or counterspell, unlike invisibility which is VSM. 

It also doesn't auto disappear on being touched like other illusions.

Keep in mind that invisible =/= undetectable though for people to actually lose your location you have to take the hide action. 

As information gathering. 

It also provides more information than the spell arcane eye with the cost of being visible.  You can both see and hear using your senses that means it can use things like truesight, devil sight, witch sight and see invisibility.

Also unlike arcane eye or a familiar, this illusion can likely go through walls/doors  and can't take damage. 

I don't think that the illusory clone can move through walls, because it actually walks to the location you desire, implying that it doesn't just float and actually connects to the ground in some capacity.  So I'd rule that you can't phase through walls with the clone.

But nothing in the spell says it's intangible. 

Quote from FatJacksBBQ >>

But nothing in the spell says it's intangible. 

 This is true! The spell does not say one way or another.

Major Image is permanent at higher lvl. And then I can cast invisibility and get some of the same effect. 

your duplicate has your hp total as its a copy of you. it does not disappear after 1 hit.

Quote from DragonbornDM23 >>

Is anyone reminded of stealth elf from sky landers when they look at this spell?

 Yeah i get that feeling

I don't get how a spell could be intangible and not be able to go through walls, is it physical or not?, because if it is then you could "gesture"it to open a door, if it is not Physical you could walk it through a wall. You can't have something that is both physical and non physical at the same time, moreover casting this spell and it be stopped by a door even though its whole point is to mislead a character seems redundant to alot of its uses. This would purely be used in combat if it can't open doors and there is no benefits to using this over invisibility. So either has to work for it to be a spell that isn't just invisibility with some flair.

Like astral projection without the risks?

Quote from DesmondDentresti >>

dfmjr, with no limit in the spell the answer is that you can be anywhere, even on other planes ... You can cast Mislead in one of the Nine Hells and then cast Plane shift and use the double as your body in Hell while you are relaxing in the Prime Material plane. 

 Wouldn't that make it an Astral projection?!

Quote from AshtonSurespell >>

If I am reading the spell correctly, you use your action to cast the spell, your body turns invisible, and a illusory duplicate appears in your place, but you have to wait until your next turn (or use another action if you action surge) to move it. If that's the case this doesn't help much during combat if the goal is to deceive an enemy into chasing your duplicate.

Also, if you did use it that way and a creature was in melee range of you, as the duplicate left, and took an opportunity attack, would it hit you or the duplicate? Would there need to be a roll involved? I'm not sure if it was meant to be used directly in combat or not.

 I would say this is the type of spell you use before combat or out of combat.

My question is, since you can see through the illusion, would you be able to use a spell with range of sight around a corner or from a distance? Where would it originate, the original caster or the illusion?