Hohige
Explorer
Can we do it without Simulacrum cheese?
Otherwise my build is a Vuman War Wizard (Alert, Metamagic Adept [Subtle spell], Elemental Adept, Int 20, Dex 16, Lucky) with infinite Simulacrums he's wished in himself (plus a few he just created normally, meaning - unlike your Simulacrums - they retain their 9th level spell slot)
He also has at least one Demiplane holding glyphs of warding containing every single concentration spell in the game (all also either cast by the Simulacrums, or wished in by the Simulacrums who retained their 9th level slots, triggering burnout if necessary), and he has just danced around triggering all of them before emerging to challenge your Sorcerer (meaning he's currently buffed with every single concentration buff spell in the game).
He orders one of his Simulacrum to Plane shift him in wherever you are as close as I need to be triggering combat.
He has +13 to initiative, with advantage on the Dex check due to one of his buffs, and an extra 1d4 from another one, and a Lucky re-roll... so we can safely he goes first (as do his infinite Simularums, should he bring them along). Foresight and Alert render him impossible to be surprised either.
I havent bothered to calculate his stats, because every single buff spell in the game is a lot of buff spells.
Among other things, he's immune to hit point damage (invulnerability), and spells of 8th level or lower (Globe of invulnerability), invisible, mind blanked, mirror imaged, mage armored, hasted, blessed, spirt guardian flitting about etc etc etc
Do his infinite simulacra also come with him?
HAhaha, OMG. Thank you very much. The Sorcerer's Twinned Simulacrum, infinite. I didn't know if you noticed, but the Sorcerer can do it. Glyph of Warding is a cleric spell (divine soul also gets it) The sorcerer now has access to any magic he didn't have and has infinite twinned and with metamagic. All Simulacrum with Wish Spell. Your Theory Crafting is really boring
You give the Sorcerer a Simulacrum-Cheese with Twinned and Metamagic.