At what range does the dragon spot you if your coming across a wide open field?
Before you spot it.
No. It never got a chance to move.
No. "The dragon can take 3 legendary actions, choosing from the options below".
None of those options are moving.
https://www.dndbeyond.com/monsters/16782-ancient-red-dragon
Yes and it takes the first one at the end of the Monk's turn! That is when you take Legendary actions. You don't understand the rules.
This is right in the link you provided:
The dragon can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature's turn.
The Monk ends his turn and the Dragon prones the Wizard and flys away.
Again, dead creatures deal no damage.
But he isn't dead when he will prone the Wizard
Mind Sharpener
When the wearer fails a Constitution saving throw to maintain concentration on a spell, the wearer can use its reaction to expend 1 of the item's charges to succeed instead.
So you keep saying this is not situational but you provide an example where the person upcasting CME requires an Artificer in the party who prepares an infusion just for him?
I have said many times it is situationally awesome, and needing not just another character but an Artificer sho uses an otherwise weak infusion for the level to make it work is an EXTREME example of being situational
But that's only for emergencies.
If this doesn't work, neither will 1/3 the other classes.
I provided examples in play of 7 actual high level fights yesterday where it would have been a waste or would not have worked. You were asked to provide a hypothetical of when it would and still haven't.
The one hypothetical example you did provide included an entirely SITUATIONAL party make up to demonstrate its effectiveness and still would not have worked.
I don't think WotC monsters negate melee build very often.
They don't, but they will negate this CME build quite often.
Now if you shot a little lower - a 8th level CME from a Sorcerer 14/fighter 6 using quicken spell and action surge .... it would be pretty darn effective, reliable and not situational. But it would not have this 500 hit points effectiveness like what you tried and failed to demonstrate.
ok. So the monk drag you within 60", and walk the rest of the way at the start of your turn.
The Dragon still flys away between your turn and the Monk's turn. What do you not understand about this?
And keep in mind this is a set piece example, where you purposely have a Monk that can drag you into combat, where you had time to precast the spell for some reason and where you won initiative (or more accurately chose a mix of allies so you would).
Your still assuming it gets a turn.
No I am not. If the Monk gets a turn the Dragon gets a Legendary action.
The only way it gets no Legendary action before its turn is if it wins initiative ... in which case it just breathes on you and flies away.
New monk feature lets you drag friends around as a bonus action + dash.
Yeah you have a friend to drag you around so your spell can be effective.
That is what would be called situational.
Ok fine.
You're level 17 (get that last EB blast).
The scout lets you know there is a dragon up ahead. The party buffs you and waits.
You ride your horse charging into the dragon lair.
With +9 initiative, you likely win, and get first strike.
There is a small chance the dragon survives till round 2.
60' move speed, 120' with a horse + 180'+ with a monk, +9 and advantage on concentration saves + qbsorb elements + auto-succed on concentration checks.
Highly situational example! Your party gets first strike with the Monk dragging you. The Dragon gets second strike with his Legendary action
Also you are riding a horse somewhere that a Dragon can't fly?
I prepared. Also, not the only way of doing it.
Ready a Scorching Ray and have someone use Dimension Door. For instance.
Ok. It is obvious you either don't know the rules or have not done a lot of high level play with a caster. If you ready Scorching Ray you need to drop concentration on CME .... so then you do no damage at all because the Dragon is immune to Fire damage. (2024 PHB page 373, 2014 PHB page 193).
IF you are ignoring rules on things like Concentration and Legendary actions it is an entirely different situation.
Oh and I guess now you have added a 5th party memer since Dimension Door is not on the Artificer or Ranger list.
Against the Tarrasque this won't work. But that's a rare case. And you can just cast fly on the Gloomstalker and let him take care of it.
You claim it is a rare case but can't come up with an example creature it will work on.