You did this. You get to read it. And you get to be the judge of how I did.
Very recently, I had deigned to take a thought exercise: Trevor Belmont versus the entirety of the Monster Hunter World roster alongside Iceborne. I personally thought that it was going to take two days tops... it took over a week to complete.
So naturally, when I finished it and posted it, I asked a fellow mutual what they thought of the accompanying poll and long story short, they brought up how Trevor would do against a Tonberry. I had no idea what a Tonberry was, and the both of you seemed to be in on an elaborate inside joke. Usually, I wouldn't care, but... my interest was piqued, so I took a peek and well...
Fuck you both.
Here I was, thinking that a Fatalis, a creature that abhors even the strongest of mortal men, could not possibly have any opponents. But no, the elaborate worldbuilding, system, and power levels have all been completely torn to shreds. The rules... are broken. And that's the point.
Now, I know that powerscalers and worldbuilders alike like to have some structure and rules, but I have a concept that I don't know has ever really been discussed, and those are the rulebreakers. Rulebreakers are characters or other creatures that don't match up against anything that has already been established in that world and no real explanation is ever offered up to try and reason out why that is.
There are actually a decent amount of examples of this in media, some specifically being Saitama from One Punch Man, the Spiral Power in Gurren Lagann, and Fatalis from Monster Hunter. These are characters, creatures, or concepts that not only break the obstacles in their path, but completely break how that world functions or operates. It has to change after the fact or wither away.
So with that being said, this doesn't mean that isn't bound to the worldbuilding in any way. Saitama is still a regular guy, Spiral Power has to be harnessed by a person's spirit, and Fatalis can still be more or less cut down in order to be stopped, but they still have those characteristics as things that fundamentally break the rules!
The Tonberry, based on what I've found on the wiki (thank the editor that summarized it nicely), is described as a formidable enemy, and given how it attacks, I am inclined to believe it. The way that it's battle strategy is described is as such (thank the editor that summarized it nicely for anyone reading it):
In battle, Tonberries advance towards the player party and, when close enough, use their signature Chef's Knife attack, which either does massive damage or instantly kills a party member. If attacked, they counter with Karma, doing damage to the attacker based on how many enemies they have slain. (Source)
So with that information alone? Yeah, it definitely qualifies as a rulebreaker.
However, I did a little bit of digging and uh... this little guy can miss the stab. And it'll stumble a bit. This is actually really fucking embarrassing for it. This is like, the easiest fight ever. And remember the point I made about rulebreakers still being tied to the world and its rules? I do! It has to get close enough to stab you. And guess what Trevor has that Tonberry doesn't? His whip. You really thought you got me, didn't you?
Ah, but there's one more thing to consider: Everyone's Grudge, or Karma. If it gets hit, it gets to land a counterattack that's equal to how many enemies are killed by the person attacking, right? Admittedly, this could be a problem as the amount of monsters Treffy's killed is the equivalent to how much bread I've eaten in my life. However, there could be ways around this.
One option is to hit it so hard that it dies instantly instead, but these things have a lot of health. Another could be to somehow corral it into a deep hole with a lot of sharp things at the bottom. And there's also what could classify as an 'attack'. A gentle shove could be interpreted any other way, no? And the way that it works, does a Tonberry decide what an attack is? If you picked up a Tonberry, would you be able to throw it off a cliff and kill it instantly? Could you pick up a Tonberry? Because they've been characterized as quite klutzy. They can even trip! So they could trip on a landmine or something.
Anyway, that's besides the point. The point is, there are ways around this. The whip could grab the knife and snatch it. That's not an attack, that's a maneuver. If you disarm the Tonberry, it's fucked.
So here's my final verdict for the both of you: If Trevor knows what he's dealing with, a 65% chance that he's beating the Tonberry. If not, then he's getting insta-killed.
