INTERMISSION: FROM A PARALLEL WORLD WHERE INITIATIVE AND STEALTH WORK AS
@Hohige PLEADS HIS DM TO RULE IN HIS FAVOUR
(In Which the Flaw of the Stone Chicken Strategy, while Nice to Prevent any Clone or Resurrection Attempt, and Visually Fun, Is Exposed).
Unknown wizard (UW): "most of my friends have been disappearing. I am truely wondering what's happening... Let's find out!"
Wizards casts Gate, naming their friend."
A stone chicken appears. the UW is perplexed and dismiss his gate immediately, then casts Dispel Magic on the stone chicken, returning the Wizard to his previous form.
UW: "my friend, what happened?"
Former Chicken (FC): "I don't know, I was in my study, then suddenly a Private Sanctum popped and I was transformed into a chicken, then was unaware of my surrounding until you released me".
UW: "OK... Who did that to you?"
FC: "I don't know."
UW: "OK, let's find out after a long rest."
UW proceeds to cast Scrying repeatedly at the Stealthy Wizard. It can take some time.
Possibility 1 : at some point, the Sorcerer drops Mind Blank and is scryed upon successfully. Totally unaware of the fact the spell is being cast on him, he has no possibility to react as initiative was never rolled.
Method A : the Old-School Assassin
Through Scrying, the UW observes the Sorcerer, then casts Greater Invisibility on his Simulacrum of a 20th level Alert Assassin (using his Concentration)., then teleporting him to the scryed location. The assassin is aware of the location of the quarry but can't see him. The quarry has no way to know someone teleported nearby, lacking any visual cue. The Assassin then proceeds to move toward the last known position of the quarry, still being hidden, without any possibility for the quarry to react to his presence. Once within 10 ft, the Assasin's blindsense defeats hiding, and he decides to attack, giving away his location. Since he's attacking a surprised target, he can use his assassinate feature to make a critical strike, so his damage roll will double, to 2d6 (shortsword)+14d6 (save CON for half due to wyvern poison) + 20d6 (sneak attack) for a total of 36d6 (average, if the save against poison is made of 101 damage), doubled if a CON 19 save isn't made against the Death Strike Feature. On the next round, having +5 DEX & being Alert & Lucky, odds he'll beat the initiative roll of +1 of the Sorcerer is great (actually, 94%), attacking for an additional 1d6+10d6+14d6(CON save for half), finishing the Sorcerer, who never add the opporunity to act.
This Sim-dropping is repeated each day until it works, should it fail. That was easy!
Method B : The Wily Wizard
The UW casts Greater Invisibility on his Simulacrum of himself, who proceeds to cast Detect Thoughts. The UW then teleports the Simulacrum to the area he scried upon. The Simulacrum is aware of the presence of creature through Detect Thoughts, and begins prying at his mind. Since there is no visual cue, the Sorcerer still can't roll Initiative. The Simulacrum then yells "WHAT IS YOUR NAME?" while probing. If the Lazy One fails his DC19 WIS save, this information will be acquired and the Simulacrum will teleport away to the UW. If he succeeds, the Simulacrum will Teleport away anyway. The same operation will be repeated daily until it works, and then Gating the Sorcerer to face a Simulacrum'd Assassin daily will be a triviality. This solution allows the UW to eat chips while he watches the Sorc being assassinated, which has added entertainment value.
Possibility 2: the Sorcerer is hiding on his demiplane. Scrying can't locate him there. Then, when the Sorcerer's goes back to the Prime, he's under mind blank and can't be targeted by Divination spells. ==> After a few days, the UW deems his strategy uneffective, but deducts that since the Sorcerer must be casting daily Mind Blank (8th level), Demiplane (8th level), which is impossible and therefore must be cast using a 9th level slot, and Planeshift (to get back to the prime), he has no fine control on where he appears back and can't cast more than one single 7th level spell when encountered. Which in itself is a limitation of the build we didn't know (and in fact, while the Wizard doesn't knows it, it's only 6th level spells that are available since the 7th level will be taken by an Extended Aid upcast according to the build). And we're back to the Lazy One build who never can do anything out of fear of being discovered, but this strategy was denied by the OP earlier in the thread, when he said that his extended security measures only applied when he prepared for a strike against a Wizard-to-be-turned-stone-chicken.
So, since the dropping of Mind Blank ends in unescapable death at the hands of an Assassin, how are you keeping Mind Blank on both you, your Simulacrum and the DMM 24 hours a day?