The HUGE AoE of this spell makes it fantastic for boss fights!

WHY would you choose this over fireball 

Con save instead of Dex. MUCH larger area. No explosion to call the rest of the bad guys in the dungeon. Maybe there’s stuff in the area you don’t want on fire. 

Better save stat, doesn't alert everyone in the kingdom that it happened, larger aoe, and cool factor.

the problem is the material component cost 

But you get to keep the Powder for future uses.

Quote from Baney >>

But you get to keep the Powder for future uses.

 Wouldn't that be consumed in the casting?

Quote from Shazrand >>

Quote from Baney >>

But you get to keep the Powder for future uses.

 Wouldn't that be consumed in the casting?

 Nope.  Most components aren’t (the exceptions are specifically listed).  Otherwise it would be prohibitively expensive to be a spellcaster.

They used to call these “focuses” in older editions, but with Spellcasting focuses also existing, the devs decided nomenclature was confusing.

Quote from brovick >>

WHY would you choose this over fireball 

 

 9 times larger area

Because Fireball is OP and constantly using it is boring.

Nice spell but unless you are first in the initiative order your going to have to figure out how NOT to include your party members in the AoE as your tanks rush up to meet the baddies. Its a necromancy spell so an evocation wizard can't sculpt pockets of safety. Maybe a Sorcerer with careful metagagic?

Con is not a better save than Dex, its very similar in most cases, but sometimes even worse because by the time you can cast this spell, you'll be very hard-pressed to find a monster with a Con below 16. The radius is nice and it does seem to extend through cover, but freezing sphere has the same radius, 10d6 cold (necrotic is lauded as being a really good damage type, and while devils and demons aren't resistant to it like they are cold damage, elemental adept exists and a lot of undead are resistant or straight immune to necrotic) and can restrain creatures in water. This spell is cool but it needs to do at least 10d6 and maybe have a secondary effect.

Does the spell consume the components?

Nope! Just pay 500 gold upfront and no more money spent

Why is this not available for Death Domain Clerics?  Come on it has "Death" in the name.  Please add it to the Death Clerics spell list.

Quote from Mad_Cow >>

Why is this not available for Death Domain Clerics?  Come on it has "Death" in the name.  Please add it to the Death Clerics spell list.

 Domain spell lists only ever go up to 5th level spells, while this is a 6th level spell

On dndbeyond there are roughly 170~ monsters that are resistance to fire and roughly 120~ that are immune to fire.

Meanwhile there are roughly 80~ that are resistant to necrotic and roughly 65~ that are immune to necrotic.

So there are roughly twice as many monsters that will ignore some or all of fireball's damage than would ignore some or all of circle of death's damage.

GENERALLY SPEAKING, not knowing any details about what kind of creatures you'll face in a particular campaign, you'll probably do more overall damage using a spell with necrotic damage rather than fire.

Quote from Ryuma >>

Nice spell but unless you are first in the initiative order your going to have to figure out how NOT to include your party members in the AoE as your tanks rush up to meet the baddies. Its a necromancy spell so an evocation wizard can't sculpt pockets of safety. Maybe a Sorcerer with careful metagagic?

 This actually makes for a better "bad guy " spell than a PC spell. Wreck the party with it in the first round, and watch them panic.

If I am inside the rope trick room, can I cast this from inside and not be affected?

Quote from Ginraden_Surviaen >>

If I am inside the rope trick room, can I cast this from inside and not be affected?