Magellan has eaten the Doku Doku no Mi, a very powerful Paramecia-type Devil Frui that allows him to generate and manipulate poison. His most infamous technique is a three-headed dragon called the Hydra; the attack is composed of corrosive liquid poison that causes lethal nerve-paralysis and melts the victims at the same time.
Magellan’s ultimate attack is Venom Demon: Hell’s Judgment which appears as a gigantic, skeletal-looking demonic beast, and Magellan has stated that the poison used is powerful enough to “destroy Impel Down itself.” Not only is the poison more lethal and caustic than Hydra, but it also spreads out from any surface it touches, literally “infecting” everything, including stone.
There’s no confirmation in the series, but considering what we know about Paramecia Awakenings (giving you greater control of the environment) and what we’ve seen Magellan do, it’s possible that he has awakened his devil fruit.
# DONQUIXOTE DOFLAMINGO
Doflamingo ate the Ito Ito no Mi which grants him the ability to create and manipulate strings. He usually moves his fingers accordingly to bend them as he pleases for either manipulating people like puppets or bifurcating his targets. The strings are extremely thin and some may even be invisible, making it almost impossible to notice and avoid them.
Using his “Parasite” move, Doflamingo forces comrades to fight (and even kill) each other, while Doflamingo himself sits at the sidelines and watches. He has shown himself capable of controlling large amounts of people at the same time without any apparent effort.
The strings can also be used for cutting, allowing Doflamingo to effortlessly slice off body parts and destroy weapons. He can also glide or fly in midair by attaching his strings to clouds, creating a “Sky Path”, as seen when he did so to cross over the seas to reach Punk Hazard from Dressrosa.
Doflamingo’s mastery of his Devil Fruit is so advanced that he was able to awaken his powers, being able to even turn his surroundings into string.
# CAHRLOTTE KATAKURI
Katakuri ate the Mochi Mochi no Mi, a special Paramecia-type Devil Fruit that lets him create, control, and transform into mochi at will. His mochi is extremely thick and adhesive, allowing him to trap even extremely strong enemies with it, although it loses its effectiveness when exposed to moisture. The fruit allows Katakuri to avoid physical attacks seemingly like a Logia user, although instead of the attacks simply going through his body, he uses his superior Kenbunshoku Haki to predict where he’ll be hit and change the shape of his malleable mochi body accordingly to dodge with minimal movement.
He frequently uses these abilities in hand-to-hand combat, sprouting several tendrils of mochi on his body to act as extra fists or legs; he can imbue these tendrils with Haki to deliver hard punches and kicks. By concentrating mochi into a single fist, Katakuri is capable of delivering punches of devastating power.
Katakuri has also awakened his Devil Fruit powers, enabling him to transform inorganic material into mochi, enhancing the range of his attacks and capture field.
# GILD TESORO
Tesoro ate the Gol Gol no Mi, which allows him to manipulate gold he has touched at will. He can use this power to create huge fountains of liquid gold, trap his enemies, and infuse gold dust and flakes into other people’s bodies so that he can then slowly transform their skin into gold. He is also able to create gold armor that grants increased power and defense.. He can manipulate it to the extent that he can create and pilot a massive golden golem, the size of a skyscraper.
Since consuming his Devil Fruit he has been able to awaken its powers, furthering the range of his influence over gold and enabling him to use all of the gold in Gran Tesoro that he has touched as a complex sensory network. Through this he is able to detect attempted break-ins or attacks on the city. When utilizing large gold constructs he is also capable of unleashing focused light beams or explosive force that have an incredible destructive power.
Bullet ate the Gasha Gasha no Mi, a Paramecia-type Devil Fruit that allows him to disassemble inanimate objects and assemble them into anything he wants with his mind. With this power, he can form a large variety of mechanical creations, most notably creating exoskeletons to significantly augment his physical power.
Bullet has awakened his devil fruit, allowing him to disassemble objects from a greater range. With his awakening, he can essentially restructure the landscape of entire islands by assembling their features as he sees fit, and create and inhabit a colossus whose physical presence is unparalleled.