Roaring or rather growling it started searching for Nil with a frenzy unlike any other.
But the only moving entity it could see is the last cat that was running behind them before still running towards it's direction.
'Take that.' Nil thought using the time the cat was looking at the other incoming cat to stab it in the neck with the second nail he had with him.
Attacking the cat in the neck, he swiftly grab it's neck from behind, locking it in place not allowing it to thrash around.
"Annoying."
Nil pinned it to the ground with one hand using his body also to hold it in place while drawing the nail he plunged into its neck earlier widening the wound along the way.
He is trying to kill it as fast as possible before the last one gets to him.
When the last cat sense the smell of blood, it quickened it's pace and hurried even more when it saw one cat dead with pool of blood under it and the second one being pinned to the ground.
Nil have deactivate the invisibility skill and thus the cat can see him which make it increase the frenzy at which it run at him activating the speed boost skill
"Shit, just die quick." Nil thought seeing the third cat pouncing in his direction.
However the cat did not die and it was Nil who had to retreat from the cat as the third cat would have crash into him if he hadn't.
Taking the nail out of the cat it quickly disappear with him from the third cat view as the nail became invisible as Nil too.
However the cat did not look around trying to find the culprit, but instead jumped at the direction it last saw the nail.
"Smart, but useless." Nil said.
Tilting to the side faintly in order to avoid the attack, but did not follow with an attack.
He did not want to kill it quickly and rather watch it get confused by the invisible grim ripper it is fighting.
And the cat became confused in earnest and jump in some directions trying to figure out where Nil is.
He even trick it a couple of times by making his claws appear to the cat briefly before pulling it back while he will quickly move out of the way as the cat crashes at the spot it last saw the nail.
"I think it's time to end this." Nil said.
The cat quickly rushed at the direction it heard the voice come from.
Although the skill mask him from being seen, that does not mean his voice can't be heard when he speaks.
Sidestepping to the side from the sprinting cat he use that opportunity to attack it's exposed side.
Searching for the attacker while whimpering from the attack, the cat finally thought of escaping from the invisible enemy.
Humans have always feared the unknown, and that act is something not bound to human alone but to every being, even this cat too.
What is more terrifying than the unknown, it is the unknown that can deal real physical damage!
"No, you ain't going nowhere."
Nil could easily deduce what it is thinking of doing from the expression it has on his face.
Without waiting for it to run away, he attack it a couple of times dealing massive damage to it's body.
He made sure that the attack land on place that has been exposed on it's body before, and with the cat focussing on fleeing at that moment did not actively block the attack.
[Ding!]
[You have slain a beast at the second round of body fortification.]
The timely announcement of the system coincided with the time the cat made it's last whimper.
"Let's be done with this quick." Nil said kneeling beside the cat tearing into its flesh.
"This is the process I hate the most." He grumbled to himself.
"I think I should get an assistant when i return to the kingdom."
After removing the cores from the three cats, he then clean his hand with the sand he pick around him before throwing the cores inside of his inventory.
"I never put this one there before." Nil said while bringing out the rest of the cats core he have killed before from his pocket.
And among the cores, one if them shone brightly than the rest which is clearly the core from the cat that is at the Liquid gathering realm.
"There you go." He muttered as he throw the cores inside of the inventory.
"Hmm, what next?" Nil thought, deep in expression, contemplating where he is suppose to advance to now.
"Ah, almost forgot. I was following the trail to where it leads to." He said sharply before he started following the trail again.
He deactivated his invisibility skill before he started following the trail, he wouldn't want to be deprived of mana.
Although he could still maintain the skill for hours, he still deactivate it nonetheless, since he doesn't know if he will encounter a powerful adversary.
Being deprived of mana could put him in a very bad position in situations like that.
Following the trail hasn't been much of a hassle, once in a while he have been encountering more cats heading to the same direction the footprints he is following lead to.
Which further solidified his assumption that the howl— or rather meow, is like a summon to call the other cats.
All the cats he encounter, he did not waste the opportunity.
He quickly attack them, without letting others notice him.
And because the cats he is killing, the other cats are bound to notice that some of their brethren is missing which might worsen his infiltration if their dead bodies are found.
So the new ones he have been killing, he started keeping their corpse in his inventory.
"I'm sure my inventory space will be look more like a pool made if blood." Of course that is a joke he made to amuse himself.
The system inventory is a space that does not have time, which means anything in there is suspended in there cannot age, neither will it degrade.