I am leveling an aberrant mind sorcerer and am mapping my spell list.  The character is the self-styled herald of an evil far-realm entity, and most of his spells are focus on mind manipulation and psychic damage. 

With regard to 9th-level spells, I have considered picking up Psychic Scream, with is thematically on target.  However, it feels very underwhelming when compared to the other 9th-level mook-killer, Meteor Swarm.  The tactical benefits of Psychic Scream include Int save, psychic damage, and the ability to select targets within range (to a maximum of 10).  However, the damage is less than half of that of Meteor Swarm, and the value of the stun condition is wholly unclear to me.  With transmuted spell metamagic, Meteor Swarm's liability against fire resistance and immunity can be wholly mitigated.  Thus, the spell's only downside is its Dex save.  While not great, Dex is also not the worst, and even if a target makes the save, the Meteor Swarm will do more damage than Psychic Scream if the save is failed. 

Under what conditions would Psychic Scream's stun prove invaluable?  It seems to me that the best CC is a dead mob, and on a sorcerer Meteor Swarm can do this better than Psychic Scream.  The scenario of having 10 high-level minions with middling Intelligence and more HP than can be addressed via Meteor Swarm seems niche to me. 

The character has no other fire spells.  In fact, all of his damaging leveled spells do psychic damage, so transmuted spell metamagic would be for the sole benefit of Meteor Swarm.  Nevertheless, I just cannot see the value of Psychic Scream over Meteor Swarm beyond character fit.  Please help me change my mind.       

Psychic Scream is far more often useful. Meteor Swarm needs a good amount of space between you and the enemy to avoid the blast radius. (Unless you're an evocation wizard. Careful spell is not good enough.) Meteor Swarm is the spell for battlefields. And yes, its damage is absurd compared to other 9th-level spells.

The stun effect isn't that likely to happen at high levels, but it's very strong when it does.

Also, Psychic Scream makes heads explode. That's very important. :)

Thanks for the response.  I appreciate the thoughts, though you seem to validate my concern.  The stun is the main selling point relative to Meteor Swarm.  If there is no compelling scenario for its use, or it cannot be expected to work routinely, then Psychic Scream presents a safer and much less effective version of Meteor Swarm.

I can think of at least one way to use the stun (assuming that it does stick).  Quicken Psychic Scream, cast it and stun a group of mobs within 30', then use Warping Implosion (same turn) to teleport away and group them all in one place (will fail Str save due to stun) to be hit by another party member AoE during same round or my Hunger of Hadar next round.  While an interesting thought experiment, Meteor Swarm might have killed them all in one go...    

Funny thing is, at 9th level spell use, damage is kind of a secondary concern when you are a caster. You basically have a village/army destroyer spell ready, but during a usual skirmish you will find Meteor Swarm to be overkill that just sits there eating up your spell choice. Compared to Wish, Gate, or even Time Stop which allows creative play and storytelling, Meteor swarm always felt like a BBEG spell unless you are actively in a 'giant armies meeting on a battlefield' game. Out of the two spells, I personally feel a adventure campaign will find you using Psychic Scream more often in engagements. The spell has a range of ANY TARGET WITHING 90', that is a 180' diameter with your character at the center.

Psychic Scream is the kind of spell you drop when you are halfway through a challenging fight, but it feels like you are still on the fence as to who is going to come out ahead, then BOOM they lose their heads. Some may become stunned until they make their save, which could be never. Others will be trying to figure out what the dark, sticky is that just splashed across their faces only to realize that it is their buddies faces.

The BBEG will probably make the save, but suddenly the loss/stunning of the support staff means you have way more option. Jump the BBEG before his folks break free, or start taking that sweet advantage to light up all the staff that still retained heads.

Quote from Xenzakkaz >>

Thanks for the response.  I appreciate the thoughts, though you seem to validate my concern.  The stun is the main selling point relative to Meteor Swarm.  If there is no compelling scenario for its use, or it cannot be expected to work routinely, then Psychic Scream presents a safer and much less effective version of Meteor Swarm.

 If you're not an evoker wizard, it's going to be really hard to use meteor swarm without friendly fire.

Also, I did a quick skim of high-CR monsters, and Int save proficiency and really high Int are both pretty uncommon.

Also, sometimes "what fits the character" is way more important than "what does the absolute most damage". Psychic Scream is a good spell. I used it on a high-level warlock, and wasn't sorry I took it. It wasn't Power Word: Tacnuke, but we had the wizard for that.

Quote from Xenzakkaz >>

 

With regard to 9th-level spells, I have considered picking up Psychic Scream, with is thematically on target.  However, it feels very underwhelming when compared to the other 9th-level mook-killer, Meteor Swarm.

The character has no other fire spells.  In fact, all of his damaging leveled spells do psychic damage, so transmuted spell metamagic would be for the sole benefit of Meteor Swarm.  Nevertheless, I just cannot see the value of Psychic Scream over Meteor Swarm beyond character fit.  Please help me change my mind.       

 I'm all about going with spells that are less about "how much damage can I do" and more about "how much would this fit in with the character's personality/beliefs".  I have a Bard who was leveling up and ultimately decided against an ability score increase to take the "defensive dueling" feat because he almost died in the campaign.  He then decided to learn the Thunderclap Cantrip, Thunderwave and Shatter - all very similar except for range - just so he could introduce himself as "Thunderbard".  I also have a very short-tempered and angry Hafling Sorcerer who likes to set things (and people) on fire so many of his spells are chosen just based on that.  D&D is, after all, a role-playing game, and I think there is a lot of inherent value in staying true to your character over just maximizing damage rolls.

As others have said, unless you're an evocation wizard meteor swarm is more likely to be a liability than a benefit, as it has a high opportunity cost since you need to get your turn early enough to use it before there are allies in the way. By comparison psychic scream is surgical so it can be used at any point during a battle, plus it targets a much less common saving throw with a much less commonly resisted damage type, so overall I'd say it's dependable in more situations.

Causing a creature to be stunned can be an incredibly powerful effect, but capitalising on it is somewhat up to your party; any party with effects that can impose conditions wants to drain the enemy's legendary resistances if they have any, and using a combination of spells with nasty rider effects is a good way to do this, a Monk dishing out Stunning Strikes can also do this very quickly. Once an enemy is stunned they lose their entire turn, which is a huge deal for a high level enemy in terms of personal and party defence, plus everyone gets advantage on attacks against a stunned target, which will often mean more damage inflicted due to not missing than the extra damage meteor swarm would have done.

Only the paralyzed condition is really stronger, but the spells like hold monster that impose that only target a single creature and the condition is the only effect, with nothing on a successful save, so they're much riskier, whereas psychic scream you're rarely going to achieve nothing by casting it (target would need to be immune or counterspell etc.).

So it's a surgical multi-target damage spell with an uncommon saving throw and a rarely resisted damage type, that can impose one of the strongest conditions in the game which has both offensive and defensive benefits, and also it explodes heads. What's not to love, especially if it fits your theme?

By the time you're high enough level to cast 9th level spells, you have a base spell save DC of 19. You're also using TCoE if you're an AM sorcerer, so let's say you get a +2 Bloodwell Vial. Then you have a spell save DC of 21, which means you need at least a +1 to Intelligence saves to succeed. If you don't have a bonus to Int saves, the stun is permanent.

And it explodes heads.

Thanks all.  Your comments have reassured me of the value of Psychic Scream, particularly since it is a solid fit for the character.  

In general Psychic  Scream is MUCH better.  Stunned is a lot better than the extra damage you would get from meteor swarm.

The times I would say MS  is better is when the enemy has immunity to stunned (Tiamat), or legendary resistance and you don't think you will run him out of them or a very good intelligence save.  In most other cases PS is going to be better because of stunned.

Quote from Xenzakkaz >>

Thanks all.  Your comments have reassured me of the value of Psychic Scream, particularly since it is a solid fit for the character.  

 My main advice is to use it often. My biggest disappointment with my aforementioned warlock is that I never actually exploded any heads. :(