¯\_(ツ)_/¯

I don’t really think so. I mean, first of all Mukuro beat them once before, and that was when he was fifteen and most of his life had been spent either as a fugitive or shut up in a lab (though it amuses me to think that Mukuro had been repeatedly jailbreaking like the Vindice was some twisted baby illusionist bootcamp). 

You can argue that Mammon didn’t have their full powers in the Ring Battle, but to me Mammon’s main problem isn’t their raw power, but their fragile mental and emotional state, as well as their lack of clarity. They get over-emotional about things very easily, and they tend to have an all-or-nothing mindset, and that can be pretty fatal when you’re engaged in a battle of the wills. It results in the kind of crash-losing we see happening repeatedly with Mammon. 

By lack of clarity I mean that I don’t think Mammon has a very clear sense of who they are, and what they want out of the world. At one point they were going on about money, but I think that’s mainly just a defense mechanism to cover up the fact that Mammon really doesn’t know what they want, that’s what they think  a sly, self-serving illusionist should want. They clearly demonstrate some kind of loyalty to Xanxus, but then flip-flops on that either due to cowardice or some self-defeating, insecure impulse. 

I mean, it’s pretty obvious that Mammon has a massive self-worth problem. It’s fine to have an egomaniacal little trip when they’re faced against a far less experienced and powerful opponent, but it’s a lot less fine to swing to the other extreme and start having an emotional breakdown at the first sign of someone overpowering them. That’s a recipe for disaster.

In stark contrast to this is Mukuro’s utter calm, confidence, and cunning in all combat situations - at all times, really. As insane as he might seem to certain others who’ve led very different lives, Mukuro is self-consistent. (”Method in the madness”, as the saying goes.) He knows who he is, he knows what he wants, he knows how to achieve it. He knows what his strengths and weaknesses are, and that sense of self is unshakable by external wins or losses. He does not doubt himself when it comes to battle. He does not second-guess. He trusts his own judgement, and he doesn’t dwell on miscalculations or failures. He moves on from things. All that are invaluable skills that many will never learn even after they’ve been through many trials, and that is what makes Mukuro a terrifying opponent and scarily competent leader.

I mean, compare their battle strategies. Mukuro has backup plan upon backup plan, and he literally only stops fighting when he’s out cold, and he never, even once, panics. Everything, including failure, is already in his calculations, and death is always a possibility, treated as equally likely as winning. As much as we like to call him an egomaniac, he’s not, not really. He’s confident because he has reason to be - in most situations, he can expect to win. And then there’s Mammon, who pulls out the all-or-nothing plan at the first opportunity, basically betting their victory on chance, and not even having enough self-awareness to factor in their own wavering will and emotional instability. They never even considered the possibility that Fon might have better faith in himself than they do.

Given equal battle capabilities, no matter who his opponent is, Mukuro can almost always come out on top, and that has more to do with will than skill. Look at the ruthlessness and decisiveness with which Mukuro dispatched Spade’s iilusions. He thrust the Khakkhara through the clones of his loved ones without hesitation, even when his senses have been completely taken over. That level of faith in his own judgement and clarity of thought can be a deciding factor in an illusionist fight. (Unfortunately for him, Spade is even more convicted, far more experienced and powerful, and was never going to fight him properly to begin with.)

You know what I’d like to see? A fight between TYL!Fran and Spade. Or better yet, TYL!Fran and Mukuro against Spade. Spade has reached that level of powerful, desperate, and depraved where he’s barely even human anymore. He’s whittled himself down to little more than a spectre. Like a comically evil version of Mukuro, how Mukuro presented himself in the beginning, except for real. Talk about the power of obsession. (But then, hilariously enough, he’s the one who’s utterly devoted to the Vongola. Ironic, indeed.) (Also, talk about inversions. Spade went from a fully functioning human to a single-minded shade; Mukuro went from a vengeful spirit to a fully mostly functioning human.)

This is a really good post because I think something the fandom tends to do is look at the word "arcobaleno" and think that truly DOES mean they're the most powerful right now. But the thing is, they were the most powerful of their GENERATION. That's why Checkerface is looking for new ones by the end of it! there's better people out there who can be the strongest.

I think TYL Fran is a really underestimated figure in the "strongest illusionist" discussion because he doesn't actually show much of what he does, but the thing about TYL Fran is that he is implied to be the most powerful under his silly persona.

and im actually not saying this because im a fran stan. im saying because there's so much hinting that he could be stronger than even mukuro, but we don't know for sure.

spade thinks mukuro is afraid of tyl fran, which is actually hinted at in the present arc to be because he thinks fran is incapable of fear. and that's a reasonable assumption because of the 666 ring and how it works

spade outright acknowledges fran as ridiculous in terms of power. he's not just skilled, he's an incredibly experienced, highest class level illusionist. that's...that's huge praise

lussuria in an interview suggests that fran might be strong enough to leave and fran is like "i mean i probably could but xanxus is here, yknow" --- if i recall correctly, the only other character we know for a fact that has successfully rejected the varia is shamal, a guy who uses biohazard war crimes on kids who annoy him

(translation courtesy of mochipanko)

and then we get to the "only 3 illusionists who can trick us" thing like you mentioned, op. it's probably an empty statement, but there's actually a third contender for this role.

Checkerface.

Who canonically tricked them into becoming Arocbaleno.

So imagine if you will --- Fran is included with Mukuro, who has an actual limit to how many times he can trick the Vindice. But despite being Mukuro's apprentice, this statement implies he's closer in comparison to Checkerface, because...

the fact that they know fran can do this, but he did it again successfully without them even considering him? that sure implies he doesn't have a limit. especially since....oh shit, whats this?

Present Fran is ALSO capable of tricking the Vindice.

In fact, he's strong enough that Mukuro is shown to be actually upset with himself for relying TOO much on him. He may not be as skilled as TYL Fran, but present Fran is talented enough to trick the Vindice.

Ultimately: There's very real implications to the idea that Mukuro would find himself relying on present Fran. TYL Fran is understandable, but a child who was never even involved with the mafia? What even IS This kid?

And you know, the scariest part about his power thing is that we KNOW Tyl!Fran wasn't Mukuro's apprentice for long. Because the first escape attempt didn't work. That's why the Kokuyo were separated. But we know that at some point, Fran joins the Kokuyo and helps him escape by himself without the help of even Chrome.

Worse, Byakuran didn't KNOW he existed in association with Mukuro. So this + the 3 illusionist lines means the Vindice KNEW Fran existed, he was doing SOMETHING to tell them they knew he existed, but no one knew he was Mukuro's apprentice to tip them off to why Mukuro was leaving.

In other words: this is mostly all Fran. He's Mukuro's apprentice, but he's skilled without Mukuro anyway.

short form writers look at people writing 100k+ fics as though this is some sort of talent given as part of a fae bargain, that the commitment required shows some sort of ungodly mental fortitude.

okay