Will the critics finally be silenced? What's next? Here's what we learned after Conor McGregor created history by adding Eddie Alvarez's lightweight title to his existing featherweight prize.
How does McGregor's achievement compare?
A legion of cage legends have not even attempted to make the gargantuan leap into a second weight category, much less challenge the No 1 fighter from the division above. In rolling the dice and staggeringly hitting the jackpot, McGregor has gone above and beyond the landmark achievements of Georges St-Pierre, Anderson Silva or Jon Jones.
McGregor has not defended either of his belts, unlike that esteemed trio of UFC greats, so that must be taken into consideration. But equally, in measuring McGregor's bravery to jump up by 10lbs, it must be noted that St-Pierre, Silva and Jones never considered it wise to embark on a meaningful run outside of the safe-haven divisions that they owned.
BJ Penn and Randy Couture held UFC titles in two weight divisions at separate times but McGregor has even trumped them by wearing gold on each shoulder. To have done so within the space of a year (and finding time to fit in a double-header against Nate Diaz at welterweight, a third weight division) is an accomplishment at the forefront of anything that any UFC fighter could boast.
Isn't McGregor supposed to struggle against wrestlers?
The perceived method of defeating McGregor (take him down, hold him down) received another slap in the face as Alvarez's accomplished wrestling credentials failed to impose themselves. It's not the first time McGregor has beaten a wrestler so will this theory crumble, as Alvarez did?
The first time the Irishman overcame the grappling acumen of an American opponent, his victim was Chad Mendes in the summer of 2015, yet critics refused to shy away. Mendes was a last-ditch replacement for the injured Jose Aldo and, although he successfully dragged McGregor to the canvas for extended periods, eventually succumbed to a knockout.
The short-notice arrangement of that fight meant McGregor was castigated in some quarters for benefiting from Mendes' lack of fitness. This time around, nullifying Alvarez's take-downs must carry more weight. Alvarez enjoyed a full training camp of planning how to put McGregor on his back yet never came close to doing so.
The snake-hips and constant threat of a counter-punch from the featherweight champion means he is becoming an increasingly difficult target to wrestle to the ground.
Why has nobody found an answer for his trademark punch?
The vicious left fist of McGregor - the same weapon that yielded his first UFC title, and previously dragged him up the ladder of contenders - accounted for the durable Alvarez. They know it's coming, but they can't get out of the way.
A skilled puncher who stands southpaw is a rare commodity in the world of MMA so McGregor's stance has a uniqueness that is even more pronounced than it would be inside a boxing ring. The left hand is almost always delivered perfectly straight (he doesn't often throw hooks or uppercuts) and comes from an angle that opponent after opponent has found too difficult to suss. It possesses a power which means that one strike can befuddle the victim - Alvarez was never the same after surviving the first knock-down - meaning a repeat becomes likelier and likelier.
But the real key behind McGregor's punching style, honed in Irish boxing gyms before he ever removed his shoes to step into a cage, is his unrivalled accuracy. Alvarez has made a career of throwing wide, powerful hooks (that's how he dethroned Rafael dos Anjos to become champion) but they are energy-sapping efforts that infrequently find the perfect home. McGregor throws short and straight, and nobody yet has found an escape route.
Is McGregor the top pound-for-pound fighter in the world?
The official rankings before Saturday night had McGregor fourth - behind No 3 Daniel Cormier, second-placed Dominick Cruz and top dog Demetrious 'Mighty Mouse' Johnson. Can any of that trio claim to be better than McGregor now that he is a two-weight champion?
McGregor's sole UFC defeat to Nate Diaz must come into play here, because it represents an imperfect resume. However, light-heavyweight champion Cormier has also lost to Jon Jones so McGregor must automatically leapfrog him, at the very least.
Cruz and Johnson, the bantamweight and flyweight champions respectively, are a sensational duo who aren't automatically demoted due to McGregor's increasing brilliance. They have fought each other, with Cruz winning, so Johnson also has one UFC blemish on his record. The pair are masters of their craft who blend all aspects of the sport seamlessly while rarely taking damage, but neither have put a run together that compares to McGregor's.
The looming return of Jones, the exiled former light-heavyweight champion, adds to the competition for the fantasy No 1 spot but he can't be considered until his suspension ends. As it stands, the argument for keeping McGregor off the top spot has dwindled to sheer bias.
When will he be back?
Another fascinating layer of intrigue surrounding the Irishman's story is how frequently we see him inside the cage. He has managed to fit 10 fights into a mere three-and-a-half year UFC stint, including turning around from his Diaz defeat within five short months. He still rushed back, the prospect of creating history in New York City proving too tempting.
Yet a post-fight announcement that his girlfriend is expecting their first child (imagine the ferocity of a mini-McGregor running around in a couple of decades) implies that Conor Sr is approaching his first major break since his remarkable takeover began.
He has already indicated that a potential return could be as far more than a mere fighter. McGregor, fully aware of his status as the UFC's most popular star, has indicated that the company's new owners must invite him into the boardroom if they want to appease his ambition.
"People have shares in the company, celebrities. Conan O'Brien owns the UFC nowadays, so where is my share? Where is my equity? If I'm the one that's bringing this. I mean, they've got to come talk to me now, that's all I know.
"I've got both belts, a chunk of money, a little family on the way. If you want me to stick around and you want me to keep doing what I'm doing, let's talk.
"But I want ownership, I want equal share, I want what I deserve, I want what I've earned."
His grand plan would represent a breakthrough in what any sportsperson has ever been capable of, yet is remains a pipe-dream. His last pipe-dream? Three years ago, he claimed he'd become a UFC two-weight world champion…