( Content Warning) I'll use [Control Particles] to create a vortex of air.

The idea brought a smirk to Rimuru's face, one that immediately informed the humans staring at him (at least, those of whom didn't have their eyes helplessly drawn to his voluminous glutes, still dripping the blood of thousands of men whose deaths had been caused literally effortlessly by the titan sitting before them) that he was about to make another move, the notion of which caused a wave of despair to wash across the remaining 14,000 men present. It had been made starkly clear to every person present that the efforts of humans had no hope of bringing harm to the ruler of the Jura Tempest Federation. Yet, few found they had the strength to attempt a retreat, and fewer still felt they had any hope of successfully fleeing if they tried.

Thus, the entire army was rooted to the spot as Rimuru's enormous body began moving once more. He slid forward off his perch atop the cliff, his butt thoroughly mulching any bodies that had managed to stay intact beneath it as it was dragged across the ground, and leaving an enormous bloody smear in its wake. His feet once more touched down on the ground far beneath the cliffside, his blood-soaked cheeks now even more prominent in the humans' lines of vision, their lecherous jiggling causing bits of crumpled metal, cloth, and wood to rain down toward his feet.

"Eugh...Can't you guys die a little more hygienically? I really don't want this stuff sticking to me all day. Maybe I should **** the rest of you to clean this mess off me, heeheeheehee! Hm, maybe another time. I wanna' try the idea I just had, so I'll clean it up myself."

Rimuru proceeded to use [Gluttonous King Beelzebuth]'s [Predation] ability to absorb the remains of the crushed humans through his skin, and allowed its [Rot] ability to decompose the matter before adding the mass to his current form. Consequently, his rear got a slight bit plumper, further increasing its ability to draw the gaze of the soldiers gathered behind him, leaving the number of men not staring at Rimuru's giant ass countable on two, maybe three hands. Even King Edmalis himself found it difficult to keep his vision focused on the face of the monster he'd foolishly chosen to go to war against as his fear, anger, and humiliation fought amongst themselves for control of his body.

"--Urp! ...Ahhh, much better. A clean slime is a happy slime, slurp!" Rimuru brought his hands behind him and gave both his plush butt cheeks a simultaneous slap, inciting another round of jiggling which further wracked the minds of the men staring at it with feelings of arousal for a being which had just killed 6,000 people. "Well, happy is a relative term in this case. I still have lots of punishment to dole out. But I get the sense nobody's going to be stepping up to take it like that last group did. So...I'll just have to make you come to me."

With his hands still placed on his ass cheeks, Rimuru bent forward, spreading his plump buttocks and exposing the humans' eyes to the sight of his anus, nestled deep in the valley of his butt crack. He flexed it a few times, ensuring all eyes were on it, then used his [Universal Shapeshift] to make it spread open, since he didn't know how to do that just using his muscles. After that, he used [Control Particles] on the air between himself and the Falmuth soldiers now comprising the army's front line, pulling the air molecules in that area of effect toward his spread anus en masse.

Men began to scream and call out for each other as they felt the pull of the vortex on their bodies, the winds strong enough to sweep men off their feet and pull them through the air. It began with just a few, a handful of men who'd been standing a bit further forward than the rest, along with any men who reached out their hands in an attempt to save them. They were swept through the air at breakneck speed, the sight of their destination filling each one with renewed terror and humiliation. Rimuru savored their screams for the brief moment he heard them up close, before they were quickly muffled as the men voicing them were pulled into his rectum, their armored bodies tingling pleasantly as they struck his anal ring or his insides, though they weren't getting pulled deep enough to stimulate his prostate yet.

The area of effect of the vortex was increasing at a steady rate, and before long human after human was being sucked into the same butthole they had just watched their comrades disappear into, creating a sustained chorus of screams and tingles for Rimuru to enjoy. Seeing this unfold, the Temple Knights and those who stood behind them were **** to accept yet another humiliating new reality: the giant feminine monster was eating people with his ass. Although in truth, he wasn't; [Gluttonous King Beelzebuth] was only taking the sucked up air into its stomach, not the humans that entered Rimuru's bowels. They were left outside Beelzebuth's stomach, free to struggle against their fleshy surroundings and each other as they tried to escape the ass of the boss monster. The shallows of Rimuru's anal cavity quickly filled with humans, and subsequent humans being sucked in resulted in the earlier ones in being pushed deeper by what could only be described as a log jam of people.

"Nhhh...Ahahah. Would you believe this is my first time...taking it up the butt?" Rimuru taunted, not bothering to look behind him at the airspace that continued to be filled with humans being sucked toward his anus. "Taking so many guys up the ass at the same time...hahahaha! It's a good thing I plan on killing you all, I wouldn't want it getting out that the ruler of Tempest is such a huge slut!"

Soon to reach the thousand mark, Rimuru felt his anal ring being stretched wider than his shapeshifting had left it. I guess the **** of the vortex isn't quite enough to shove them deeper than this. They'll need some extra help.

Rimuru clenched his anus, resulting in a burst of pleasure as the log of struggling humans was compressed and the section of it that had proceeded past his anus was shoved much deeper inside, enough to finally reach his prostate. As he moaned aloud once more, the voice of Raphael once more sounded in his head.

<<6,136 dead.>>

Guess they couldn't handle the pressure...those guys must have been right up against my asshole when I squeezed. Imagine being killed by a giant, cute slime boy clenching his anus! These guys are seriously pathetic. I'm almost sad I didn't do this to them in real life. I might have gone overboard using Megiddo for such weaklings.

Rimuru continued expanding the area of effect of the vortex through the ranks of the Falmuth soldiers, who had been sent into complete disarray by the gradual vacuuming up of their compatriots. Many of the soldiers at the rear of the line were attempting to flee, but were being prevented from doing so by the line of Temple Knights, much as they themselves had done to the mercenary line before them. The Temple Knights, generally speaking, were of the mind that if they allowed any of Falmuth's soldiers to flee, the vortex would continue into their own ranks, whereas ensuring all of the line in front of them was sucked up would satisfy the monster lord before they were subject to that fate. There was also the fact their doctrine forbade one from turning away from a monster they had sworn to strike down.

Rimuru's Anal Vortex attack lasted for around seven straight minutes, after which Rimuru could feel most of his large intestine filled with humans, most still alive and struggling, while a comparative handful had been crushed by subsequent clenches of his anus. His moans of pleasure had overtaken the screams of suctioned soldiers in volume somewhere around the 3,000 mark, and a steady drip of precum had soaked the ground beneath his feet. As the Temple Knights had hoped, Rimuru finally felt satisfied once he'd gotten the vast majority of the front Falmuth line lodged in his bowels (not that he'd been keeping track), and the vortex disappeared as he lifted his torso upright once more. Some hundred or so stragglers remained outside, slumped down in front of the Temple Knights' shields in defeat, having been unable to run away nor fight back.

<<7,442 dead.>>

"Nnnooooohhh...fuuuuck! They're still...trying to get out. They're attacking...my butt! But my butt is...too strong for them!"

Rimuru's body shook in pleasure. He was holding himself back as much as he could. But there was only so much he could do with nearly 8,000 people up his ass, trying to claw their way to freedom. He knew he was at his limit. I can't...hold it back. I gotta' turn around, I can't waste this!

Rimuru spun around quickly, his cock swinging around and flinging several enormous globs of precum at the army, which bowled over handfuls of people in the Temple Knight line, the majin line, and the royal guard line with no pattern. It was with great horror that the men below Rimuru realized what was about to happen, causing shields to be raised, barriers to be erected, and a king to throw closed the flap covering the entrance of his tent and dive further inside.

Rimuru grabbed hold of his cock with both hands, doing his best to hold himself back just a little longer as his lust and fury mixed within his monster heart. "T-take this! My love, my _aaaa_anger, and all...of my...cum! Shining...Peniiiiiiiis!"

Reaching orgasm in a manner only befitting Rimuru, pleasure coursed through his human-shaped slime body, tightening every muscle it had, causing thousands of human bodies to burst inside him, while outside he burst all over several more thousands of humans. The first jet of hot, sticky, blue-tinted jizz plowed through hundreds of humans in a straight line, knocking every single one touched by it onto his ass. None were able to stop it from entering straight into King Edmalis' tent, not even Captain of the Guard Folgen and his Unique Skill [Spearhead] which had allowed him to **** several dozen shield-bearing soldiers to gather in front of him in an attempt to stay the blast.

The next spurt was launched upward in an arc, with most of it falling right on top of the first jet, collapsing the tent filled with musky slime jelly. The third spurt was aimed to Rimuru's left, launching in an arc as well, coating another line of soldiers in the hot, sticky seed. This went on for five more spurts, while Rimuru slowly moved his penis from left to right in an attempt to coat the army as evenly as possible. By the end of it, there were only around a couple thousand soldiers not coated in the slime, but stuck between lines of soldiers that were, it wasn't much consolation.

<13,892 dead.>>

That's not 20,000, which means...I'm not done yet. But, man, that was an incredible orgasm! I was right to not just jack myself off like I would have done in my last life! Actually, considering I'm a slime now...can I just go again right away? Even if this human form has a refractory period, I can probably just use [Universal Shapeshift] to reset my body to normal and circumvent that. Yeah, I'm not done with these Falmuth bastards just yet. They killed people I care about. One orgasm is letting them off easy.