Why is Manny Fernandez such a good goalie? It's because he's immortal and he feeds off the power of other Highlanders he kills. That's why.
I have proof that Manny Fernandez is immortal. Just look at his name. The current Manny Fernandez was "born" in 1974 in Ontario as Emmanuel Fernandez. But this is all just a cover story. There have been Manny Fernandezes for hundreds of years, and they’re him pretending to be a new person to prevent suspicion.
Before hockey, Manny Fernandez was a professional wrestler. He was known as The Raging Bull, was 90 pounds heavier, and wore a mustache as a disguise. He wrestled back before the explosion of WWF/WWE when there were dozens of organizations across the country. But wrestlers like him helped put the "sport" on the map.
Here he is trying to cut off the head of another wrestler with his knees, but they aren't sharp enough to do the job. But look at all the blood, he was close. And remember, Highlanders get more power when they cut off people's heads.
Before wrestling, Manny Fernandez, under the pseudonym Manuel Jose Fernandez, was a football player. He played nose tackle for the Dolphins back in the 70s. He won a pair of Super Bowls with Miami, and was a member of that 1972 team. Now doesn't he look eerily similar to the Manny Fernandez in the wrestling clip?
Why does he look the same? Because he's the same guy! He lost a few pounds to wrestle, then lost some more to play hockey. He trimmed the mustache then got rid of it completely for the NHL (a mustache in a goalie's mask would get very irritating).
Before getting into sports, Manny Fernandez was a military man. Going under the name Manuel J. Fernandez, he was a fighter pilot in the Korean War. He was credited with 14.5 kills, making him the 3rd leading Ace amongst American pilots. He also served as an instructor during WWII, and as a fighter escort during the Berlin Airlift. Notice how he's just starting to grow the mustache?
Before fighting for the US in Korea, he fought against the US in Cuba during the Spanish-American War. Then he was known as General Manuel Fernandez Silvestre. After withdrawing from Cuba with the rest of the Spaniards, he fought in Morocco. After the Disaster of Annual, it's believed he shot himself in the head. HOWEVER, nobody ever found his body, or saw him die. How come? Because he didn't die, he just changed his identity and shaved that ridiculous mustache.
Before fighting for the Spanish, he fought against the Spanish. Manny Fernandez has no loyalties but to himself. Back in the 1810s, he fought in the Mexican War of Independence. He eventually rose to the rank of Major General in Santa Anna's Mexican Army. Then his name was Manuel Fernández Castrillón. He fought the Texans at the Alamo, but to his credit pleaded for several prisoners to be spared. Later, his death was staged as Texas's inevitable victory in the war became apparent.
Manny Fernandez has lead many lives in his never-ending lifetime. He was a soccer player in 1940s Spain with the name Manuel Fernández Fernández, and the nickname Pahiño. As Manuel Fernández Juncos he founded the Puerto Rican Red Cross, and wrote the lyrics to Puerto Rico's national anthem.
It's impossible to really know when Manny Fernandez was born. We know he's at least 230 years old, but he could be 500, 1,000, or 2,000 years old. What matters is that he's immortal (unless he gets his head chopped off) and he's extremely powerful. With him, the Boston Bruins have an excellent chance at winning The Prize, a.k.a. the Stanley Cup.