Although the Rat King had been successfully incapacitated, mauled, crippled, and brought to the brink of death, Toz didn't relax. Despite having every piece of its body pierced by the metal spikes, the Rat King still wasn't dead. Not even having its eyes and brain punctured instantly killed it.
But even if it refused to die, it at least couldn't move, and it didn't seem to be able to use magic either as it just twitched and wriggled in the pitfall. However, even with its entire body torn open by the spikes, the Rat King didn't bleed as much as one could expect. Thanks to the Rat King's natural regeneration, its wounds were trying to close up around the spikes, keeping the blood inside.
The Rat King definitely couldn't move or think or get out of the current sticky situation it found itself in, but if it continued healing, there were no guarantees it wouldn't be able to absorb the mana in the spikes as soon as it began recovering.
If the Rat King recovered and escaped from the most powerful trap that Toz and Nil had made, they really wouldn't have a way to deal with the Rat King at the moment. Despite Toz faking his exhaustion, he wasn't in exactly a prime condition either.
Since Toz couldn't let the Rat King recover, he brought out the cats of the familiar space so they could begin trying to kill it for good. With the Rat King trapped and unable to react right in front of them, the only difficulty lay in figuring out a way to actually permanently extinguish its life.
Toz had noticed that the Rat King used up a lot of its energy and mana every time it healed, so he decided to go for that angle. Now the only question was in which way should he torture the Rat King first.
Since the spikes were already at the ready and still filled with Toz and Nil's mana, it was a pretty warm-up.
Toz took control over the spikes embedded in the Rat King's body, manually triggering and resetting the trap. He pulled all the spikes except the ones piercing the skull out of the Rat King in a spray of blood and flesh as the barbs tore away at the Rat King's body.
As soon as the thorns left the Rat King's body, the wounds began closing up. Broken bones realigned. Bundles of muscles stitched together by veins. Fresh skin covering the regrown tissue.
And then, right before the Rat King started moving and by instinct, trying to get away from the spikes littering its head, Toz sent the spikes right back into the Rat King's healed body.
Unlike the mess they made when they were retracted, the spikes entered the Rat King quite smoothly. It would have been even smoother if not for the Rat King twisting and whimpering in pain.
After driving the spikes in as deep as they went, Toz pulled them out again. Then let the Rat King heal up a bit. Then sent the spikes right back in.
While Toz, with the help of Nil, manipulated the spikes to continuously let the Rat King use up all its mana to heal itself, Mindle and Lucy also attacked the Rat King.
Mindle got to work trying to fry the Rat King's brain from the inside out using the thorns that were lodged in its skull. She hadn't forgotten that she almost died only a few weeks after being born. She vented the feelings of helplessness and frustration that had arisen then, and been suppressed until now, on the Rat King.
The metal spikes piercing the Rat King's brain turned red hot, and the sloshing and squishing sounds escaping from the pitfall were joined by the sizzling of fried rat meat.
Lucy didn't have any efficient ways to directly attack the Rat King, like the other three did, so instead, he experimented with the less physical aspects of darkness. Things like the darkness of the mind and hallucinations. Nightmares.
Although the Rat King was already brain dead and as far away from conscious as a living being could get while still alive, Lucy still managed to stir its mind awake. The nearly collapsed consciousness of the Rat King was easily molded and played with by Lucy thanks to the state the Rat King was in.
The Rat King repeatedly being pierced and healed. Having its brain roasted. The whimpers of horror, not pain, that escaped its mouth when it wasn't burned or nailed shut. The sight of it all had Toz wondering if he should feel pity for it for being subjected to such inhuman acts. The pain and suffering the Rat King must be going through was practically unimaginable, not to mention the psychological torture of a tiny cat finding a new favorite toy to play with.
But if the Rat King would just die already, it wouldn't suffer as much. And it wouldn't be fair to hold three beings that weren't humans to the standards of what was humane or not. There was also the justifying feeling of every life that would have been lost in the hands of the Rat King if it hadn't been stopped.
Although, justification didn't really matter to Toz since he didn't feel guilty about tormenting the Rat King while trying to kill it. He was, however, slightly worried about how others would see it, and if maybe the Explorer's guild would hold it against him or his cats in the future.
Unlike with what had happened in the mountain range with Mindle's egg, the Scorched Earth Rats and their King wouldn't be so easily let go. Toz wouldn't be able to ignore the consequences and the follow-up of him dealing with the Rat King.
The mountains collapsing had just been some strange event that didn't really affect anything. The Scorched Earth Rat King was a calamity that if gone unchecked, could ruin at least an entire plane, and if not stopped, the Scorched Earth Rats would continue spreading like a plague to other planes connected through the portals.