I dont see the spell.. so how do i do this..

So, not actually detecting good and evil. 

This spell should be named Detect Extraplaner beings

Quote from davdwilliams >>

This spell should be named Detect Extraplaner beings

 Except undead aren't necessarily extraplanar, and the spell doesn't detect extraplanar humanoids (such as gith) or extraplanar constructs (such as modron).

Would this spell reveal Gargoth in the Shield of the Hidden Lord? 

This turned into a useless spell.

Completely agree... How does the title of the spell match the function in any way?

Shouldn't it though... at least to a certain extent?

I have a question: my player cast this and was under attack by an Invisible Stalker (which remains invisible during attacks). It is an elemental, so the PC knows it's there and knows it's location, so does the Invisible Stalker still get Advantage to hit the PC and does the PC still have Disadvantage to hit the Stalker?  

Quote from Grimscale >>

I have a question: my player cast this and was under attack by an Invisible Stalker (which remains invisible during attacks). It is an elemental, so the PC knows it's there and knows it's location, so does the Invisible Stalker still get Advantage to hit the PC and does the PC still have Disadvantage to hit the Stalker?  

 They would know where it is, but still not be able to see it, so yes, Advantage/Disadvantage still applies.

It just means they would not be swinging around wildly hoping they are in the right spot.

Quori are aberrations as per RAW or fiends if you ask Keith Baker. Either way, they would be detected

Can it detect an intellect devourer inside someone's head?

A possibly really stupid question:

Assuming you successfully detect one of those creature types (fey, fiend, etc.), is your character able to tell which creature type it is?

It is up to your DM, as a DM I would say yes, since it is an aberration.  Then I would reward the player with inspiration, since that is really smart... This would happen just before the devourer burst out is the person's head and attacks because it was discovered.

Agreed. Detect outsider (if outsider was still a thing) would be a good alternative. 

The radius of the sphere is 30 ft.

In the range/area description of a spell, the number referring to a spherical range of effect indicates its radius, not its diameter.

The radius of the sphere is 30 ft.

In the range/area description of a spell, the number referring to a spherical range of effect indicates its radius, not its diameter.

they're abberatons https://www.dndbeyond.com/monsters?filter-type=0&filter-search=quor&filter-cr-min=&filter-cr-max=&filter-armor-class-min=&filter-armor-class-max=&filter-average-hp-min=&filter-average-hp-max=&filter-is-legendary=&filter-is-mythic=&filter-has-lair= 

we do though Quori are aberrations https://www.dndbeyond.com/monsters?filter-type=0&filter-search=quor&filter-cr-min=&filter-cr-max=&filter-armor-class-min=&filter-armor-class-max=&filter-average-hp-min=&filter-average-hp-max=&filter-is-legendary=&filter-is-mythic=&filter-has-lair= 

Check the dates before you start calling people out.

The comments are from 2018. At the time of that posting, Wayfinder's Guide to Eberron was the only Eberron material available. There was no Rising From the Last War. We did NOT have stats at that time for Quori.