In this thread, i'll be talking why zoro was far from his full when he was fighting Killer. Also, i'll be mainly talking about his endurance, not his strength.
Firstly, let's take a look at how great was zoro's endurance pre TS
1. Orange Town Arc
Buggy seemed to miss zoro's vital, but still left a serious wound as mentioned by Buggy himself and shown by zoro sweating excessively
After taking such a grieving wound, zoro decided to take luffy along with the iron bars which consequently made the injury worse
After that, zoro decided to take a quick nap in a house there. While having a nap, the house zoro rests in got destroyed by a buggy ball
Here's showing the destructiveness of a buggy ball
With his injury still kicking in, he couldn't do nothing but to fight Cabaji in order to escape.
While fighting Cabaji, he got kicked two times right on the spot of his injury
Even after all of that, zoro decided to handicap himself by piercing his own wound using his sword
With those relatively serious injury, zoro still managed to stand up and won the fight. This shows the high level of pain tolerance of pre TS zoro
2. Baratie and Arlong Park Arc
Mihawk was surely holding back else zoro would've been dead. That said, it still speaks volume for how great zoro's endurance was.
He then went to Nami's village and fought one of Arlong's officers, Haachi
While fightinf Haachi, zoro suddenly fell because of the injury he had from Mihawk, he started to sweating heavily suggesting the injury he had was severe
He then stood up knowing that there's still an enemy in front of him, he received one body slam from Hacchi
Even after defeating Hacchi, he then proceeded to stall Arlong so that he could buy time for Sanji saving luffy from getting drowned
While doing such task, zoro received one damage dealt by Arlong
Surprisingly, zoro was still able to move and even irritated Arlong of how great zoro's endurance was
All of those were still not enough to take down Zoro, Usopp even mentioned that it would've taken 2 years to recover from such injuries for a normal human. i know this is a hyperbole but it's still a sign of Oda trying to show us how great zoro's endurance was. Even Sanji was getting confused how possibly could zoro still moving after taking such injuries
Then again, this shows how great zoro's endurance was even pre TS!
3. Alabasta Arc
In Alabasta, zoro was challenged to his verge of death to be able cut steel, he fought Mr 1. While fighting him he took some grieving wound
Imagine he got two fricking rotating blade like beyblade, thrown to a building, and received a powerful slash right in his chest, and he was still able to roaming around.
In the rendezvous point, he helped Vivi and Chopper to go up a building leaving his injuries getting worse
Then again, this shows how great zoro's endurance was
There are more other instances of zoro showing great feats of endurance, in Thriller Bark for example, he received his own injuries + luffy's injuries and was still able to maintain his conciousness. However, i can't cover all those materials because it'd be too much.
Since the Timeskip, zoro fainted only once when fighting against Killer. Honestly speaking, i expected more from zoro but turned out he got knocked out by a single stab attack from Killer, i was kind disappointed. However i then saw a panel asserting that it's not solely because of Killer's attack, it was also because of the hunger and possibly the poison that collectively collected in Zoro's stomache since by the time his arrival in Wano
At least, there are 3 reasons why zoro fainted during that time
1. Solely because of Killer's attack
Firstly, we know the fact that Zoro was still able to move after that attack, if Killer's attack was supposed to be that lethal, it should've taken on zoro for good similar to how Killer got knocked out right away. Also, as i mentioned, Unlike punch-inflicted-injury, it's easier to compare stab wounds by just looking how deep was the cut, pre TS zoro tanked a stab wound from Buggy and was still able to perform more tasks as i mentioned before, supported by the other evidence that i provide showing how great zoro's endurance was. At least current zoro is 10 times stronger than pre TS zoro, so we can expect current zoro's endurance is 10 times stronger than pre TS zoro's.
2. Hunger
This argument may seems ridiculous to some, but it's okay and let's talk about it. Firstly, we know that there is a sound coming out of zoro's stomach indicating that he was hunger when he fight Killer. Secondly, we know that pre TS zoro was able to fast for 9 days straight
First argument seems to support this assumption, but second argument seems to refute this assumption. So to compromise and fuse these two arguments, the mosy probable is that the injury zoro received fron Killer prevented zoro from withstanding his hunger longer
3. Poison from the food he had eaten
We know the fact that zoro had been eating poisonous foods for days. Also, the sound shown in the panel may also indicate that it was zoro's stomach having trouble because of poison
To make a single possible scenario, let's fuse those three arguments into the most probable one. So essentially:
Zoro fainted because of the injury, hunger, and poison, with poison/hunger played the major role and his injury played the minor role in making zoro unconscious
What do you think? what factor that nerfed zoro the most?
Firstly, let's take a look at how great was zoro's endurance pre TS
1. Orange Town Arc






While fighting Cabaji, he got kicked two times right on the spot of his injury



With those relatively serious injury, zoro still managed to stand up and won the fight. This shows the high level of pain tolerance of pre TS zoro
2. Baratie and Arlong Park Arc



He then went to Nami's village and fought one of Arlong's officers, Haachi
While fightinf Haachi, zoro suddenly fell because of the injury he had from Mihawk, he started to sweating heavily suggesting the injury he had was severe


He then stood up knowing that there's still an enemy in front of him, he received one body slam from Hacchi

Even after defeating Hacchi, he then proceeded to stall Arlong so that he could buy time for Sanji saving luffy from getting drowned
While doing such task, zoro received one damage dealt by Arlong

Surprisingly, zoro was still able to move and even irritated Arlong of how great zoro's endurance was

All of those were still not enough to take down Zoro, Usopp even mentioned that it would've taken 2 years to recover from such injuries for a normal human. i know this is a hyperbole but it's still a sign of Oda trying to show us how great zoro's endurance was. Even Sanji was getting confused how possibly could zoro still moving after taking such injuries

Then again, this shows how great zoro's endurance was even pre TS!
3. Alabasta Arc
In Alabasta, zoro was challenged to his verge of death to be able cut steel, he fought Mr 1. While fighting him he took some grieving wound





Imagine he got two fricking rotating blade like beyblade, thrown to a building, and received a powerful slash right in his chest, and he was still able to roaming around.
In the rendezvous point, he helped Vivi and Chopper to go up a building leaving his injuries getting worse

Then again, this shows how great zoro's endurance was
There are more other instances of zoro showing great feats of endurance, in Thriller Bark for example, he received his own injuries + luffy's injuries and was still able to maintain his conciousness. However, i can't cover all those materials because it'd be too much.
Since the Timeskip, zoro fainted only once when fighting against Killer. Honestly speaking, i expected more from zoro but turned out he got knocked out by a single stab attack from Killer, i was kind disappointed. However i then saw a panel asserting that it's not solely because of Killer's attack, it was also because of the hunger and possibly the poison that collectively collected in Zoro's stomache since by the time his arrival in Wano

At least, there are 3 reasons why zoro fainted during that time
1. Solely because of Killer's attack
Firstly, we know the fact that Zoro was still able to move after that attack, if Killer's attack was supposed to be that lethal, it should've taken on zoro for good similar to how Killer got knocked out right away. Also, as i mentioned, Unlike punch-inflicted-injury, it's easier to compare stab wounds by just looking how deep was the cut, pre TS zoro tanked a stab wound from Buggy and was still able to perform more tasks as i mentioned before, supported by the other evidence that i provide showing how great zoro's endurance was. At least current zoro is 10 times stronger than pre TS zoro, so we can expect current zoro's endurance is 10 times stronger than pre TS zoro's.
2. Hunger
This argument may seems ridiculous to some, but it's okay and let's talk about it. Firstly, we know that there is a sound coming out of zoro's stomach indicating that he was hunger when he fight Killer. Secondly, we know that pre TS zoro was able to fast for 9 days straight

First argument seems to support this assumption, but second argument seems to refute this assumption. So to compromise and fuse these two arguments, the mosy probable is that the injury zoro received fron Killer prevented zoro from withstanding his hunger longer
3. Poison from the food he had eaten
We know the fact that zoro had been eating poisonous foods for days. Also, the sound shown in the panel may also indicate that it was zoro's stomach having trouble because of poison
To make a single possible scenario, let's fuse those three arguments into the most probable one. So essentially:
Zoro fainted because of the injury, hunger, and poison, with poison/hunger played the major role and his injury played the minor role in making zoro unconscious
What do you think? what factor that nerfed zoro the most?