how does blackbeard have two devil fruits

Blackbeard is a character from 'One Piece' and is known to have two Devil Fruits. His ability to wield two such powers is quite puzzling as the canon suggests that any individual who consumes two of these will perish. Blackbeard, however, broke this rule after he took Whitebeard's Tremor-Tremor Fruit in addition to his own Dark-Dark Fruit.

Some fans hypothesize this is possible due to his unique body structure, hinted at several times in the series. Another popular theory includes his Darkness powers enabling him to host an additional Devil Fruit.

Having two devil fruits in the world of 'One Piece' is unheard of, yet Blackbeard managed to break this convention. In typical circumstances, a person dies if they consume two devil fruits. However, Blackbeard’s action was an exception that sparked countless discussions among fans. When he took the power of the Tremor-Tremor Fruit from his fallen crewmate, Whitebeard, he already owned the Dark-Dark Fruit.

It's suggested that Blackbeard's particular ability to manipulate darkness and pull anything into an abyss allows him to handle the lethal energies of two fruits. Alternatively, it’s also possible that his unique bodily feature plays a role in this irregularity as it was hinted at several points during the show.

In the universe of 'One Piece', Blackbeard, also known as Marshall D. Teach, managed to achieve the impossible - possessing two devil fruits. It’s a strange case because taking two of these fruits means certain death which somehow he defied. He originally had the Dark-Dark Fruit but later added Whitebeard’s Tremor-Tremor Fruit, leading to a surge of curious debates among fans.

An interesting theory believes that Teach’s Dark-Dark Fruit's specific qualities, which can absorb and neutralize power, plays a role in his unusual capacity of handling two seemingly lethal forces simultaneously. It's also proposed that his unique physique, as hinted earlier in the series, allows him to bend this fundamental rule of the One Piece universe.