Mostly but if someone came up with a wizard 7 or 9 CME it's worth a look maybe.
Best would be CME + Scorching Ray.
But that takes your 2 big spells and does appropriately big damage.
Some multi class character 12or 13 could probably do it buy be unplayable/weak eg fighter 2/Valor bard 10,/warlock1.
Dunno why that would be unplayable.
Warcaster and Spell Sniper.
Misty step into position.
Attack, nick (at -1), Eldritch blast * 3 = 5 attacks.
Action surge, attack, Eldritch Blast *3 = 4 attacks
= 9 attacks * 4d8 CME + (6* 1d10+4)
= 213 damage * 50% accuracy
= 106.5 damage nova.
You'd need to know about a battle 10 minutes in advance, otherwise you waste turn 1, but expetise in stealth, arcane eye, or etc can give you it most of the time.
And you have good AC (warlock slot for shield spell), bardic inspiration to toss out, and a bunch of spells.
It's not overpowered at that level, especially on longer days when you run out of CME or lose concentration (get Resilient Con next). But it's definitely playable.