I believe people on the comments section are hating too much and giving Falcon and Carlos no credit at all.
You guys keep using power levels to compare fighters, but only when its convenient for you.
Rihito got a super power up after two years training BASIC techniques from Kuroki. He went straight from underdog to defeating Mokichi, who had a 50-1 Kengan Match record.
But Mokichi also lost to Raian, who lost to Ohma. You can believe Raian is in par with the Fang and Kuroki Gensai, but he got cocky and almost every hit Ohma aimed at him went to the neck, making him lose.
¿Do you need a 300 chapter build up for every character on the series? That would take too long.
Falcon has been hyped as Idemitsu's bodyguard for all of Omega, so he has to be at least as good as Metsudo's top bodyguards. We know he was an undefeated mma champion (just like Okubo Naoya). Muteba admitted he is one of the best three in the world at not killing his opponent (wich favors him greatly in purgatory rules), and this was before Falcon disappeared from the underground scene. I favor the ninja weeb character greatly and I enjoyed it personally, but if you take into account the upgrades he got from his training, he is an absolute top tier fighter. Falcon's training has been said to focus on confusing strong opponents, and he is a former magician on top (You guys should look up the Malcon Gedo fight on Hajime no Ippo). This last bit confirms that Rihito got so strong, these techniques were taking a much bigger effect on him than they should, in fact, you can expect them to work on every Kengan Fighter except Julius.
This match is actually in favor of Rihito for having Purgatory rules. ¿Do you guys really think this guy cant pierce deeper with his throat/neck/thigh stabs? The first time he pierced Rihito on the throat, if he had gone a little deeper, he would have killed him. ¿How about the poisons? He could have coated his toes with stronger poison. ¿How about the other techniques? Ninjas are know for assassination, he could have centered his training on moves that kill their opponent instead of moves that "wreck" them.
You could say Razor's Edge here is the big unfair factor of the fight. Rihito didn't manage to land a single hit in all the match, and even with the beard's training, the most he would have got in is one good punch or kick. Rihito has Razor's Edge since he was born, and is a letal move that can take out anyone. Even if he went to train with the strongest character in the series, one would ask themselves why he isn't training grappling instead, so he can grab his opponent once and automatically win the fight.
Without Razor's Edge, this fight would have been so one-sided that it wouldn't have been fun.