Translation errors like this one affect the reader's and viewer’s perception, especially in this case, where this detail would be referenced later in chapter 299 when Gaja destroys Megicula’s body with his Ultimate Magic, revealing that Megicula’s heart is located in her head. +

The word “now” in the text implies that Zagred’s heart was originally where a normal person’s heart would typically be—on the left side of the chest—but then moved to a different location. However, the word “now” is not present in the original Japanese text, which states:
"貫いた筈の心臓が... 違う場所に...!!?" +

The following is what’s written in the official English translation, which has always been done by Taylor Engel:
“I was sure I pran his heart through... But now it's somewhere else?!!” +

We also have the Demon Tiger Pufferfish from the Land of the Sun shown in chapter 342, which mutated due to exposure to the Yoryoku (magic power) of the Five-Headed Dragon.

An example of that are the marine species living near the Underwater Temple shown in chapter 59, which according to Magna, "evolved independently because of the mana".
But in the Japanese version, Magna, like Finral, uses a specific term: "影響" (eikyou), which means "influence."

It means that someone in the distant past came into contact with Megicula, was affected in some way, and that was passed down to future generations, making humans capable of casting curses without Megicula. We know the Agrippa have a history with Megicula and centuries worth of expertise in curses.

In chapter 277, we learn that the Curse Magic of the human world came from Megicula. But pay attention to the term, "Curse Magic," not the curses themselves, but rather the ability to cast curses. In the Japanese version, the term used is "派生," which specifically means "derivation."

The interesting thing about this is that when Magna and Luck said his hair was too flashy in chapter 112, he said there was nothing wrong with it because, according to him, "I'm human, after all!!"
That was very weird.

And what seals the deal is a detail that I haven't seen anyone point out in the manga, which is the fact that IN THE SAME SCENE WHERE HE SAYS THIS, his hair is emitting black particles and there's a burning sound effect(チリチリ chiri chiri) as if it's under the influence of some kind of power.

This could be interpreted as a joke about him deciding to change his hairstyle just to get himself pumped up, like he told Magna and Luck... Until you read the original Japanese version, which says:
"魔力の影響で髪型が変わるほど特訓したってのに結局攻撃魔法覚えられないんだがら..." +

+ he says a line that was translated in the official English version as:
"I did so much special magical training that it changed my hairstyle, but I still couldn’t master an attack spell. So..."

Remember that anime scene where Vanessa is shown dyeing Finral's hair? Well... That scene never happened in the manga, and I'll explain why.
In chapter 112, Magna and Luck see Finral with a different hairstyle and don't recognize him, until Asta appears and tells them that it’s clearly Finral. ->