Some considerations:
Ainz has resistance to time-stop, I do not think this will be effective against him. In volume 7, when he himself for the time, he says that from level 70 it is necessary to acquire countermeasures against such things, and being a cautious player possessing such knowledge, it would not make so much sense he did not have; however, we have one more base: in Volume 2 he mentions having rings that give him resistance to abilities that affect time / flow.
Mention of volume 7:
Ainz vanished.
It was the same tactic as earlier.
"Teleportation!"
"Not quite."
As expected, the voice came from behind.
"I—"
Before Roberdyck could finish, Ainz's hand gently settled on Imina's shoulder. There was no hostility in that gesture.
However, it had a telling effect. All the strength in her body vanished, and she slumped to the ground. Although her mind was fully functional and conscious, her body felt like a puddle of immobile, insensate slime.
"What did you do to her?"
Roberdyck asked his question in a trembling voice, as his eyes went from the collapsed Imina to Ainz, who stood by her side.
"Was that a surprise? It's nothing special."
Ainz proceeded to explain in such a way as to break Roberdyck's spirit.
"It was almost the same as just now. After casting a silent [Time Stop] I moved over here and cast the same spell I used on that man, [Touch of Undeath]. And then, I just touched her."
The air between them froze into silence. The sound of Roberdyck swallowing was exceptionally loud in comparison,
"…You stopped time…"
"Oh yes. Anti-time stop countermeasures are very important, don't you know? You'll need to have them by the time you hit level 70. Oh well, you're going to die here, so in your case, it's largely academic."
Mention of volume 2:
However, even faster than that, Clementine used another martial art.
"ÒÇîFlow AccelerationÒÇì."
This martial art had a startling effect.
It felt as though someone had used time-controlling magic to slow time down. Everything moved slowly, as though immersed in some highly viscous fluid. The speed of Ainz's swing slowed to a crawl.
However Clementine moved at the same speed in this decelerated world. She effortlessly dodged Ainz's counterattack and approached Ainz from the front.
This might have been some sort of misperception on Ainz's part. The magic rings which Ainz wore should have protected him from temporal attacks and attacks designed to impede his freedom of movement — although there might be some unknown factor at work here.
He must have felt like she had accelerated all of a sudden because his battle with Clementine was so intense. The important thing was that Ainz had seen this martial art before, but he had not felt the same way back then.
"Gaze—"
Gazef Stronoff had used this technique before.
In this mention, it is strange: it has resistance, but is it affected? Well, as he says, he kind of misinterpreted it. Ainz mentions that he had already seen Gazef use such a technique - in fact, Gazef has already used it. In volume 1, chapter 4, he uses the explanation here:
The truth was, Gazef's arms were growing heavier and heavier, and his heart was racing.
ÒÇîInstant CounterÒÇì was a martial art that forcibly corrected the body's balance after making an attack, resetting it to before the blow was struck. While that meant that the practitioner could immediately attack again, the forced reset of the body would place immense strain on it.
ÒÇîFlow AccelerationÒÇì was a martial art that increased the speed at which one's nerves functioned, increasing one's attack rate. However, that technique created fatigue in the brai.
Well, nothing to do with temporal manipulation, it makes sense that Ainz's rings had no effect at all.
Already against teleportation, Ainz does not need the previous time to activate it; the spells that had been previously activated against Shalltear were spoken at the time of the preparation, and at no time had this ability been activated - nor is it as if he needed preparation for anything, far from it.
Anyway, the use is extremely fast:
Shalltear selected—
"—ÒÇîGreater TeleportationÒÇì."
The plan was to teleport into close range and begin melee combat.
Her field of vision distorted, but the scenery that should have instantly appeared before her eyes felt like it had been slowed down.
Cheh!
Shalltear guessed that this was the effect of the teleport-impeding spell, ÒÇîDelay TeleportationÒÇì."
As Shalltear had guessed, she was quite a distance away from Ainz, when she should have been deposited into the range of her Spuit Lance. Instead, she saw three sparkling balls of light before her eyes — made by the ÒÇîDrifting Master MineÒÇì spell.
Finally, my vote for Ainz, his instakills are based on manipulation of death, I have not seen many arguments against it here. Timestop and Teleportation is something that Ainz can handle.
I apologize for my bad English, it is not my original language.